vi: change MAX_LINELEN meaning: now it is the biggest supported

screen wigth. Introduce MAX_TABSTOP and MAX_INPUT_LEN. Fix redraw
of very long lines and cursor movement past NULs.

2 files changed, 309 insertions, 317 deletions

diff --git a/editors/Config.in b/editors/Config.in
index 3361d89f1..7c06678fb 100644
--- a/editors/Config.in
+++ b/editors/Config.in
@@ -90,14 +90,13 @@ config VI
           you may wish to use something else.
 
 config FEATURE_VI_MAX_LEN
-        int "Maximum line length in vi"
+        int "Maximum screen width in vi"
         range 256 16384
-        default 1024
+        default 4096
         depends on VI
         help
-          vi uses on-stack buffers for intermediate line buffers.
-          You may want to decrease this parameter if your target machine
-          benefits from smaller stack usage.
+          Contrary to what you may think, this is not eating much.
+          Make it smaller than 4k only if you are very limited on memory.
 
 config FEATURE_VI_COLON
         bool "Enable \":\" colon commands (no \"ex\" mode)"
diff --git a/editors/vi.c b/editors/vi.c
index e58d6b310..e1aabab01 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -33,9 +33,13 @@
 #endif
 
 enum {
-        MAX_LINELEN = CONFIG_FEATURE_VI_MAX_LEN,
-        MAX_SCR_COLS = CONFIG_FEATURE_VI_MAX_LEN,
         MAX_TABSTOP = 32, // sanity limit
+        // User input len. Need not be extra big.
+        // Lines in file being edited *can* be bigger than this.
+        MAX_INPUT_LEN = 128,
+        // Sanity limits. We have only one buffer of this size.
+        MAX_SCR_COLS = CONFIG_FEATURE_VI_MAX_LEN,
+        MAX_SCR_ROWS = CONFIG_FEATURE_VI_MAX_LEN,
 };
 
 // Misc. non-Ascii keys that report an escape sequence
@@ -46,20 +50,21 @@ enum {
 #define VI_K_HOME               (char)132       // Cursor Key Home
 #define VI_K_END                (char)133       // Cursor Key End
 #define VI_K_INSERT             (char)134       // Cursor Key Insert
-#define VI_K_PAGEUP             (char)135       // Cursor Key Page Up
-#define VI_K_PAGEDOWN           (char)136       // Cursor Key Page Down
-#define VI_K_FUN1               (char)137       // Function Key F1
-#define VI_K_FUN2               (char)138       // Function Key F2
-#define VI_K_FUN3               (char)139       // Function Key F3
-#define VI_K_FUN4               (char)140       // Function Key F4
-#define VI_K_FUN5               (char)141       // Function Key F5
-#define VI_K_FUN6               (char)142       // Function Key F6
-#define VI_K_FUN7               (char)143       // Function Key F7
-#define VI_K_FUN8               (char)144       // Function Key F8
-#define VI_K_FUN9               (char)145       // Function Key F9
-#define VI_K_FUN10              (char)146       // Function Key F10
-#define VI_K_FUN11              (char)147       // Function Key F11
-#define VI_K_FUN12              (char)148       // Function Key F12
+#define VI_K_DELETE             (char)135       // Cursor Key Insert
+#define VI_K_PAGEUP             (char)136       // Cursor Key Page Up
+#define VI_K_PAGEDOWN           (char)137       // Cursor Key Page Down
+#define VI_K_FUN1               (char)138       // Function Key F1
+#define VI_K_FUN2               (char)139       // Function Key F2
+#define VI_K_FUN3               (char)140       // Function Key F3
+#define VI_K_FUN4               (char)141       // Function Key F4
+#define VI_K_FUN5               (char)142       // Function Key F5
+#define VI_K_FUN6               (char)143       // Function Key F6
+#define VI_K_FUN7               (char)144       // Function Key F7
+#define VI_K_FUN8               (char)145       // Function Key F8
+#define VI_K_FUN9               (char)146       // Function Key F9
+#define VI_K_FUN10              (char)147       // Function Key F10
+#define VI_K_FUN11              (char)148       // Function Key F11
+#define VI_K_FUN12              (char)149       // Function Key F12
 
 /* vt102 typical ESC sequence */
 /* terminal standout start/normal ESC sequence */
@@ -150,7 +155,7 @@ static smallint readonly_mode = 0;
 
 #if ENABLE_FEATURE_VI_DOT_CMD
 static smallint adding2q;               // are we currently adding user input to q
-static char *last_modifying_cmd;        // last modifying cmd for "."
+static char *last_modifying_cmd;        // [MAX_INPUT_LEN] last modifying cmd for "."
 static char *ioq, *ioq_start;           // pointer to string for get_one_char to "read"
 #endif
 #if ENABLE_FEATURE_VI_OPTIMIZE_CURSOR
@@ -170,23 +175,31 @@ static char *last_search_pattern;	// last pattern from a '/' or '?' search
 struct globals {
         /* many references - keep near the top of globals */
         char *text, *end;       // pointers to the user data in memory
-        int text_size;          // size of the allocated buffer
         char *dot;              // where all the action takes place
+        int text_size;          // size of the allocated buffer
 #if ENABLE_FEATURE_VI_YANKMARK
-        char *reg[28];          // named register a-z, "D", and "U" 0-25,26,27
         int YDreg, Ureg;        // default delete register and orig line for "U"
+        char *reg[28];          // named register a-z, "D", and "U" 0-25,26,27
         char *mark[28];         // user marks points somewhere in text[]-  a-z and previous context ''
         char *context_start, *context_end;
 #endif
         /* a few references only */
 #if ENABLE_FEATURE_VI_USE_SIGNALS
-        jmp_buf restart;                // catch_sig()
+        jmp_buf restart;        // catch_sig()
 #endif
         struct termios term_orig, term_vi;      // remember what the cooked mode was
 #if ENABLE_FEATURE_VI_COLON
         char *initial_cmds[3];  // currently 2 entries, NULL terminated
 #endif
-        char readbuffer[MAX_LINELEN];
+        // Should be just enough to hold a key sequence,
+        // but CRASME mode uses it as generated command buffer too
+#if ENABLE_FEATURE_VI_CRASHME
+        char readbuffer[128];
+#else
+        char readbuffer[32];
+#endif
+
+        char scr_out_buf[MAX_SCR_COLS + MAX_TABSTOP * 2];
 };
 #define G (*ptr_to_globals)
 #define text           (G.text          )
@@ -204,6 +217,7 @@ struct globals {
 #define term_vi        (G.term_vi       )
 #define initial_cmds   (G.initial_cmds  )
 #define readbuffer     (G.readbuffer    )
+#define scr_out_buf    (G.scr_out_buf   )
 #define INIT_G() do { \
         PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
 } while (0)
@@ -266,12 +280,12 @@ static void standout_start(void);	// send "start reverse video" sequence
 static void standout_end(void); // send "end reverse video" sequence
 static void flash(int);         // flash the terminal screen
 static void show_status_line(void);     // put a message on the bottom line
-static void psb(const char *, ...);     // Print Status Buf
-static void psbs(const char *, ...);    // Print Status Buf in standout mode
-static void ni(const char *);           // display messages
+static void status_line(const char *, ...);     // print to status buf
+static void status_line_bold(const char *, ...);
+static void not_implemented(const char *); // display "Not implemented" message
 static int format_edit_status(void);    // format file status on status line
 static void redraw(int);        // force a full screen refresh
-static int format_line(char*, char*, int);
+static char* format_line(char*, int);
 static void refresh(int);       // update the terminal from screen[]
 
 static void Indicate_Error(void);       // use flash or beep to indicate error
@@ -363,7 +377,7 @@ int vi_main(int argc, char **argv)
         {
                 char *p = getenv("EXINIT");
                 if (p && *p)
-                        initial_cmds[0] = xstrdup(p);
+                        initial_cmds[0] = xstrndup(p, MAX_INPUT_LEN);
         }
 #endif
         while ((c = getopt(argc, argv, "hCR" USE_FEATURE_VI_COLON("c:"))) != -1) {
@@ -384,7 +398,7 @@ int vi_main(int argc, char **argv)
 #if ENABLE_FEATURE_VI_COLON
                 case 'c':               // cmd line vi command
                         if (*optarg)
-                                initial_cmds[initial_cmds[0] != 0] = xstrdup(optarg);
+                                initial_cmds[initial_cmds[0] != 0] = xstrndup(optarg, MAX_INPUT_LEN);
                         break;
                         //case 'h':     // help -- just use default
 #endif
@@ -447,7 +461,7 @@ static int init_text_buffer(char *fn)
         return rc;
 }
 
-static void edit_file(char * fn)
+static void edit_file(char *fn)
 {
         char c;
         int size;
@@ -459,13 +473,16 @@ static void edit_file(char * fn)
         static char *cur_line;
 #endif
 
-        editing = 1;    // 0= exit,  1= one file, 2= multiple files
+        editing = 1;    // 0 = exit, 1 = one file, 2 = multiple files
         rawmode();
         rows = 24;
         columns = 80;
         size = 0;
-        if (ENABLE_FEATURE_VI_WIN_RESIZE)
+        if (ENABLE_FEATURE_VI_WIN_RESIZE) {
                 get_terminal_width_height(0, &columns, &rows);
+                if (rows > MAX_SCR_ROWS) rows = MAX_SCR_ROWS;
+                if (columns > MAX_SCR_COLS) columns = MAX_SCR_COLS;
+        }
         new_screen(rows, columns);      // get memory for virtual screen
         init_text_buffer(fn);
 
@@ -510,7 +527,7 @@ static void edit_file(char * fn)
                 while ((p = initial_cmds[n])) {
                         do {
                                 q = p;
-                                p = strchr(q,'\n');
+                                p = strchr(q, '\n');
                                 if (p)
                                         while (*p == '\n')
                                                 *p++ = '\0';
@@ -547,7 +564,7 @@ static void edit_file(char * fn)
 #if ENABLE_FEATURE_VI_DOT_CMD
                 // These are commands that change text[].
                 // Remember the input for the "." command
-                if (!adding2q && ioq_start == 0
+                if (!adding2q && ioq_start == NULL
                  && strchr(modifying_cmds, c)
                 ) {
                         start_new_cmd_q(c);
@@ -577,25 +594,21 @@ static void edit_file(char * fn)
 
 //----- The Colon commands -------------------------------------
 #if ENABLE_FEATURE_VI_COLON
-static char *get_one_address(char * p, int *addr)       // get colon addr, if present
+static char *get_one_address(char *p, int *addr)        // get colon addr, if present
 {
         int st;
         char *q;
-
-#if ENABLE_FEATURE_VI_YANKMARK
-        char c;
-#endif
-#if ENABLE_FEATURE_VI_SEARCH
-        char *pat, buf[MAX_LINELEN];
-#endif
+        USE_FEATURE_VI_YANKMARK(char c;)
+        USE_FEATURE_VI_SEARCH(char *pat;)
 
         *addr = -1;                     // assume no addr
         if (*p == '.') {        // the current line
                 p++;
                 q = begin_line(dot);
                 *addr = count_lines(text, q);
+        }
 #if ENABLE_FEATURE_VI_YANKMARK
-        } else if (*p == '\'') {        // is this a mark addr
+        else if (*p == '\'') {  // is this a mark addr
                 p++;
                 c = tolower(*p);
                 p++;
@@ -607,17 +620,13 @@ static char *get_one_address(char * p, int *addr)	// get colon addr, if present
                                 *addr = count_lines(text, q);   // count lines
                         }
                 }
+        }
 #endif
 #if ENABLE_FEATURE_VI_SEARCH
-        } else if (*p == '/') { // a search pattern
-                q = buf;
-                for (p++; *p; p++) {
-                        if (*p == '/')
-                                break;
-                        *q++ = *p;
-                        *q = '\0';
-                }
-                pat = xstrdup(buf);     // save copy of pattern
+        else if (*p == '/') {   // a search pattern
+                q = strchrnul(++p, '/');
+                pat = xstrndup(p, q - p); // save copy of pattern
+                p = q;
                 if (*p == '/')
                         p++;
                 q = char_search(dot, pat, FORWARD, FULL);
@@ -625,16 +634,17 @@ static char *get_one_address(char * p, int *addr)	// get colon addr, if present
                         *addr = count_lines(text, q);
                 }
                 free(pat);
+        }
 #endif
-        } else if (*p == '$') { // the last line in file
+        else if (*p == '$') {   // the last line in file
                 p++;
                 q = begin_line(end - 1);
                 *addr = count_lines(text, q);
         } else if (isdigit(*p)) {       // specific line number
                 sscanf(p, "%d%n", addr, &st);
                 p += st;
-        } else {                        // I don't reconise this
-                // unrecognised address- assume -1
+        } else {
+                // unrecognised address - assume -1
                 *addr = -1;
         }
         return p;
@@ -686,12 +696,13 @@ static void setops(const char *args, const char *opname, int flg_no,
 }
 #endif
 
-static void colon(char * buf)
+// buf must be no longer than MAX_INPUT_LEN!
+static void colon(char *buf)
 {
         char c, *orig_buf, *buf1, *q, *r;
-        char *fn, cmd[MAX_LINELEN], args[MAX_LINELEN];
+        char *fn, cmd[MAX_INPUT_LEN], args[MAX_INPUT_LEN];
         int i, l, li, ch, b, e;
-        int useforce = FALSE, forced = FALSE;
+        int useforce, forced = FALSE;
 
         // :3154        // if (-e line 3154) goto it  else stay put
         // :4,33w! foo  // write a portion of buffer to file "foo"
@@ -718,9 +729,7 @@ static void colon(char * buf)
         q = text;                       // assume 1,$ for the range
         r = end - 1;
         li = count_lines(text, end - 1);
-        fn = current_filename;                  // default to current file
-        memset(cmd, '\0', MAX_LINELEN); // clear cmd[]
-        memset(args, '\0', MAX_LINELEN);        // clear args[]
+        fn = current_filename;
 
         // look for optional address(es)  :.  :1  :1,9   :'q,'a   :%
         buf = get_address(buf, &b, &e);
@@ -735,10 +744,12 @@ static void colon(char * buf)
                         break;
                 *buf1++ = *buf++;
         }
+        *buf1 = '\0';
         // get any ARGuments
         while (isblank(*buf))
                 buf++;
         strcpy(args, buf);
+        useforce = FALSE;
         buf1 = last_char_is(cmd, '!');
         if (buf1) {
                 useforce = TRUE;
@@ -788,7 +799,7 @@ static void colon(char * buf)
                 if (b < 0) {    // no addr given- use defaults
                         b = e = count_lines(text, dot);
                 }
-                psb("%d", b);
+                status_line("%d", b);
         } else if (strncasecmp(cmd, "delete", i) == 0) {        // delete lines
                 if (b < 0) {    // no addr given- use defaults
                         q = begin_line(dot);    // assume .,. for the range
@@ -798,8 +809,8 @@ static void colon(char * buf)
                 dot_skip_over_ws();
         } else if (strncasecmp(cmd, "edit", i) == 0) {  // Edit a file
                 // don't edit, if the current file has been modified
-                if (file_modified && ! useforce) {
-                        psbs("No write since last change (:edit! overrides)");
+                if (file_modified && !useforce) {
+                        status_line_bold("No write since last change (:edit! overrides)");
                         goto vc1;
                 }
                 if (args[0]) {
@@ -810,7 +821,7 @@ static void colon(char * buf)
                         // fn = current_filename;  was set by default
                 } else {
                         // no user file name, no current name- punt
-                        psbs("No current filename");
+                        status_line_bold("No current filename");
                         goto vc1;
                 }
 
@@ -829,7 +840,7 @@ static void colon(char * buf)
 #endif
                 // how many lines in text[]?
                 li = count_lines(text, end - 1);
-                psb("\"%s\"%s"
+                status_line("\"%s\"%s"
                         USE_FEATURE_VI_READONLY("%s")
                         " %dL, %dC", current_filename,
                         (file_size(fn) < 0 ? " [New file]" : ""),
@@ -839,7 +850,7 @@ static void colon(char * buf)
                         li, ch);
         } else if (strncasecmp(cmd, "file", i) == 0) {  // what File is this
                 if (b != -1 || e != -1) {
-                        ni("No address allowed on this command");
+                        not_implemented("No address allowed on this command");
                         goto vc1;
                 }
                 if (args[0]) {
@@ -905,24 +916,24 @@ static void colon(char * buf)
                 }
                 // don't exit if the file been modified
                 if (file_modified) {
-                        psbs("No write since last change (:%s! overrides)",
+                        status_line_bold("No write since last change (:%s! overrides)",
                                  (*cmd == 'q' ? "quit" : "next"));
                         goto vc1;
                 }
                 // are there other file to edit
                 if (*cmd == 'q' && optind < save_argc - 1) {
-                        psbs("%d more file to edit", (save_argc - optind - 1));
+                        status_line_bold("%d more file to edit", (save_argc - optind - 1));
                         goto vc1;
                 }
                 if (*cmd == 'n' && optind >= save_argc - 1) {
-                        psbs("No more files to edit");
+                        status_line_bold("No more files to edit");
                         goto vc1;
                 }
                 editing = 0;
         } else if (strncasecmp(cmd, "read", i) == 0) {  // read file into text[]
                 fn = args;
                 if (!fn[0]) {
-                        psbs("No filename given");
+                        status_line_bold("No filename given");
                         goto vc1;
                 }
                 if (b < 0) {    // no addr given- use defaults
@@ -936,7 +947,7 @@ static void colon(char * buf)
                         goto vc1;       // nothing was inserted
                 // how many lines in text[]?
                 li = count_lines(q, q + ch - 1);
-                psb("\"%s\""
+                status_line("\"%s\""
                         USE_FEATURE_VI_READONLY("%s")
                         " %dL, %dC", fn,
                         USE_FEATURE_VI_READONLY((readonly_mode ? " [Readonly]" : ""),)
@@ -948,8 +959,8 @@ static void colon(char * buf)
                         file_modified++;
                 }
         } else if (strncasecmp(cmd, "rewind", i) == 0) {        // rewind cmd line args
-                if (file_modified && ! useforce) {
-                        psbs("No write since last change (:rewind! overrides)");
+                if (file_modified && !useforce) {
+                        status_line_bold("No write since last change (:rewind! overrides)");
                 } else {
                         // reset the filenames to edit
                         optind = fn_start - 1;
@@ -1056,7 +1067,7 @@ static void colon(char * buf)
                 }
 #endif /* FEATURE_VI_SEARCH */
         } else if (strncasecmp(cmd, "version", i) == 0) {  // show software version
-                psb("%s", BB_VER " " BB_BT);
+                status_line("%s", BB_VER " " BB_BT);
         } else if (strncasecmp(cmd, "write", i) == 0  // write text to file
                 || strncasecmp(cmd, "wq", i) == 0
                 || strncasecmp(cmd, "wn", i) == 0
@@ -1068,7 +1079,7 @@ static void colon(char * buf)
                 }
 #if ENABLE_FEATURE_VI_READONLY
                 if (readonly_mode && !useforce) {
-                        psbs("\"%s\" File is read only", fn);
+                        status_line_bold("\"%s\" File is read only", fn);
                         goto vc3;
                 }
 #endif
@@ -1091,9 +1102,9 @@ static void colon(char * buf)
                 }
                 if (l < 0) {
                         if (l == -1)
-                                psbs("\"%s\" %s", fn, strerror(errno));
+                                status_line_bold("\"%s\" %s", fn, strerror(errno));
                 } else {
-                        psb("\"%s\" %dL, %dC", fn, li, l);
+                        status_line("\"%s\" %dL, %dC", fn, li, l);
                         if (q == text && r == end - 1 && l == ch) {
                                 file_modified = 0;
                                 last_file_modified = -1;
@@ -1115,19 +1126,19 @@ static void colon(char * buf)
                 }
                 text_yank(q, r, YDreg);
                 li = count_lines(q, r);
-                psb("Yank %d lines (%d chars) into [%c]",
+                status_line("Yank %d lines (%d chars) into [%c]",
                                 li, strlen(reg[YDreg]), what_reg());
 #endif
         } else {
                 // cmd unknown
-                ni(cmd);
+                not_implemented(cmd);
         }
  vc1:
         dot = bound_dot(dot);   // make sure "dot" is valid
         return;
 #if ENABLE_FEATURE_VI_SEARCH
  colon_s_fail:
-        psb(":s expression missing delimiters");
+        status_line(":s expression missing delimiters");
 #endif
 }
 
@@ -1140,8 +1151,8 @@ static void Hit_Return(void)
         standout_start();       // start reverse video
         write1("[Hit return to continue]");
         standout_end();         // end reverse video
-        while ((c = get_one_char()) != '\n' && c != '\r')       /*do nothing */
-                ;
+        while ((c = get_one_char()) != '\n' && c != '\r')
+                continue;
         redraw(TRUE);           // force redraw all
 }
 
@@ -1199,7 +1210,7 @@ static void sync_cursor(char * d, int *row, int *col)
         // find out what col "d" is on
         co = 0;
         do {                            // drive "co" to correct column
-                if (*tp == '\n' || *tp == '\0')
+                if (*tp == '\n') //vda || *tp == '\0')
                         break;
                 if (*tp == '\t') {
                         if (d == tp && cmd_mode) { /* handle tabs like real vi */
@@ -1350,14 +1361,14 @@ static void dot_end(void)
         dot = end_line(dot);    // return pointer to last char cur line
 }
 
-static char *move_to_col(char * p, int l)
+static char *move_to_col(char *p, int l)
 {
         int co;
 
         p = begin_line(p);
         co = 0;
         do {
-                if (*p == '\n' || *p == '\0')
+                if (*p == '\n') //vda || *p == '\0')
                         break;
                 if (*p == '\t') {
                         co = next_tabstop(co);
@@ -1527,7 +1538,7 @@ static char *char_search(char * p, const char * pat, int dir, int range)
         q = re_compile_pattern(pat, strlen(pat), &preg);
         if (q != 0) {
                 // The pattern was not compiled
-                psbs("bad search pattern: \"%s\": %s", pat, q);
+                status_line_bold("bad search pattern: \"%s\": %s", pat, q);
                 i = 0;                  // return p if pattern not compiled
                 goto cs1;
         }
@@ -1811,7 +1822,7 @@ static char *text_hole_make(char * p, int size)	// at "p", make a 'size' byte ho
         cnt = end - src;        // the rest of buffer
         if ( ((end + size) >= (text + text_size)) // TODO: realloc here
                         || memmove(dest, src, cnt) != dest) {
-                psbs("can't create room for new characters");
+                status_line_bold("can't create room for new characters");
                 p = NULL;
                 goto thm0;
         }
@@ -1845,7 +1856,7 @@ static char *text_hole_delete(char * p, char * q) // delete "p" thru "q", inclus
         if (src >= end)
                 goto thd_atend; // just delete the end of the buffer
         if (memmove(dest, src, cnt) != dest) {
-                psbs("can't delete the character");
+                status_line_bold("can't delete the character");
         }
  thd_atend:
         end = end - hole_size;  // adjust the new END
@@ -1928,52 +1939,19 @@ static void show_help(void)
         );
 }
 
-static void print_literal(char * buf, const char * s) // copy s to buf, convert unprintable
-{
-        unsigned char c;
-        char b[2];
-
-        b[1] = '\0';
-        buf[0] = '\0';
-        if (!s[0])
-                s = "(NULL)";
-        for (; *s; s++) {
-                int c_is_no_print;
-
-                c = *s;
-                c_is_no_print = (c & 0x80) && !Isprint(c);
-                if (c_is_no_print) {
-                        strcat(buf, SOn);
-                        c = '.';
-                }
-                if (c < ' ' || c == 127) {
-                        strcat(buf, "^");
-                        if (c == 127)
-                                c = '?';
-                        else
-                                c += '@';
-                }
-                b[0] = c;
-                strcat(buf, b);
-                if (c_is_no_print)
-                        strcat(buf, SOs);
-                if (*s == '\n')
-                        strcat(buf, "$");
-        }
-}
-
 #if ENABLE_FEATURE_VI_DOT_CMD
 static void start_new_cmd_q(char c)
 {
-        // release old cmd
-        free(last_modifying_cmd);
         // get buffer for new cmd
-        last_modifying_cmd = xzalloc(MAX_LINELEN);
+        if (!last_modifying_cmd)
+                last_modifying_cmd = xzalloc(MAX_INPUT_LEN);
         // if there is a current cmd count put it in the buffer first
         if (cmdcnt > 0)
                 sprintf(last_modifying_cmd, "%d%c", cmdcnt, c);
-        else // just save char c onto queue
+        else { // just save char c onto queue
                 last_modifying_cmd[0] = c;
+                last_modifying_cmd[1] = '\0';
+        }
         adding2q = 1;
 }
 
@@ -2001,7 +1979,7 @@ static char *string_insert(char * p, char * s) // insert the string at 'p'
                                 cnt++;
                 }
 #if ENABLE_FEATURE_VI_YANKMARK
-                psb("Put %d lines (%d chars) from [%c]", cnt, i, what_reg());
+                status_line("Put %d lines (%d chars) from [%c]", cnt, i, what_reg());
 #endif
         }
         return p;
@@ -2104,8 +2082,11 @@ static void cookmode(void)
 static void winch_sig(int sig ATTRIBUTE_UNUSED)
 {
         signal(SIGWINCH, winch_sig);
-        if (ENABLE_FEATURE_VI_WIN_RESIZE)
+        if (ENABLE_FEATURE_VI_WIN_RESIZE) {
                 get_terminal_width_height(0, &columns, &rows);
+                if (rows > MAX_SCR_ROWS) rows = MAX_SCR_ROWS;
+                if (columns > MAX_SCR_COLS) columns = MAX_SCR_COLS;
+        }
         new_screen(rows, columns);      // get memory for virtual screen
         redraw(TRUE);           // re-draw the screen
 }
@@ -2165,40 +2146,41 @@ static char readit(void)	// read (maybe cursor) key from stdin
         };
 
         static const struct esc_cmds esccmds[] = {
-                {"OA", VI_K_UP},       // cursor key Up
-                {"OB", VI_K_DOWN},     // cursor key Down
-                {"OC", VI_K_RIGHT},    // Cursor Key Right
-                {"OD", VI_K_LEFT},     // cursor key Left
-                {"OH", VI_K_HOME},     // Cursor Key Home
-                {"OF", VI_K_END},      // Cursor Key End
-                {"[A", VI_K_UP},       // cursor key Up
-                {"[B", VI_K_DOWN},     // cursor key Down
-                {"[C", VI_K_RIGHT},    // Cursor Key Right
-                {"[D", VI_K_LEFT},     // cursor key Left
-                {"[H", VI_K_HOME},     // Cursor Key Home
-                {"[F", VI_K_END},      // Cursor Key End
-                {"[1~", VI_K_HOME},    // Cursor Key Home
-                {"[2~", VI_K_INSERT},  // Cursor Key Insert
-                {"[4~", VI_K_END},     // Cursor Key End
-                {"[5~", VI_K_PAGEUP},  // Cursor Key Page Up
-                {"[6~", VI_K_PAGEDOWN},// Cursor Key Page Down
-                {"OP", VI_K_FUN1},     // Function Key F1
-                {"OQ", VI_K_FUN2},     // Function Key F2
-                {"OR", VI_K_FUN3},     // Function Key F3
-                {"OS", VI_K_FUN4},     // Function Key F4
+                {"OA"  , VI_K_UP      },   // cursor key Up
+                {"OB"  , VI_K_DOWN    },   // cursor key Down
+                {"OC"  , VI_K_RIGHT   },   // Cursor Key Right
+                {"OD"  , VI_K_LEFT    },   // cursor key Left
+                {"OH"  , VI_K_HOME    },   // Cursor Key Home
+                {"OF"  , VI_K_END     },   // Cursor Key End
+                {"[A"  , VI_K_UP      },   // cursor key Up
+                {"[B"  , VI_K_DOWN    },   // cursor key Down
+                {"[C"  , VI_K_RIGHT   },   // Cursor Key Right
+                {"[D"  , VI_K_LEFT    },   // cursor key Left
+                {"[H"  , VI_K_HOME    },   // Cursor Key Home
+                {"[F"  , VI_K_END     },   // Cursor Key End
+                {"[1~" , VI_K_HOME    },   // Cursor Key Home
+                {"[2~" , VI_K_INSERT  },   // Cursor Key Insert
+                {"[3~" , VI_K_DELETE  },   // Cursor Key Delete
+                {"[4~" , VI_K_END     },   // Cursor Key End
+                {"[5~" , VI_K_PAGEUP  },   // Cursor Key Page Up
+                {"[6~" , VI_K_PAGEDOWN},   // Cursor Key Page Down
+                {"OP"  , VI_K_FUN1    },   // Function Key F1
+                {"OQ"  , VI_K_FUN2    },   // Function Key F2
+                {"OR"  , VI_K_FUN3    },   // Function Key F3
+                {"OS"  , VI_K_FUN4    },   // Function Key F4
                 // careful: these have no terminating NUL!
-                {"[15~", VI_K_FUN5},   // Function Key F5
-                {"[17~", VI_K_FUN6},   // Function Key F6
-                {"[18~", VI_K_FUN7},   // Function Key F7
-                {"[19~", VI_K_FUN8},   // Function Key F8
-                {"[20~", VI_K_FUN9},   // Function Key F9
-                {"[21~", VI_K_FUN10},  // Function Key F10
-                {"[23~", VI_K_FUN11},  // Function Key F11
-                {"[24~", VI_K_FUN12},  // Function Key F12
-                {"[11~", VI_K_FUN1},   // Function Key F1
-                {"[12~", VI_K_FUN2},   // Function Key F2
-                {"[13~", VI_K_FUN3},   // Function Key F3
-                {"[14~", VI_K_FUN4},   // Function Key F4
+                {"[11~", VI_K_FUN1    },   // Function Key F1
+                {"[12~", VI_K_FUN2    },   // Function Key F2
+                {"[13~", VI_K_FUN3    },   // Function Key F3
+                {"[14~", VI_K_FUN4    },   // Function Key F4
+                {"[15~", VI_K_FUN5    },   // Function Key F5
+                {"[17~", VI_K_FUN6    },   // Function Key F6
+                {"[18~", VI_K_FUN7    },   // Function Key F7
+                {"[19~", VI_K_FUN8    },   // Function Key F8
+                {"[20~", VI_K_FUN9    },   // Function Key F9
+                {"[21~", VI_K_FUN10   },   // Function Key F10
+                {"[23~", VI_K_FUN11   },   // Function Key F11
+                {"[24~", VI_K_FUN12   },   // Function Key F12
         };
         enum { ESCCMDS_COUNT = ARRAY_SIZE(esccmds) };
 
@@ -2208,11 +2190,11 @@ static char readit(void)	// read (maybe cursor) key from stdin
         // get input from User- are there already input chars in Q?
         if (n <= 0) {
                 // the Q is empty, wait for a typed char
-                n = safe_read(0, readbuffer, MAX_LINELEN - 1);
+                n = safe_read(0, readbuffer, sizeof(readbuffer));
                 if (n < 0) {
                         if (errno == EBADF || errno == EFAULT || errno == EINVAL
-                                        || errno == EIO)
-                                editing = 0;
+                         || errno == EIO)
+                                editing = 0; // want to exit
                         errno = 0;
                 }
                 if (n <= 0)
@@ -2225,10 +2207,11 @@ static char readit(void)	// read (maybe cursor) key from stdin
                         struct pollfd pfd[1];
                         pfd[0].fd = 0;
                         pfd[0].events = POLLIN;
-                        // keep reading while there are input chars and room in buffer
-                        while (safe_poll(pfd, 1, 0) > 0 && n <= (MAX_LINELEN - 5)) {
+                        // keep reading while there are input chars, and room in buffer
+                        // for a complete ESC sequence (assuming 8 chars is enough)
+                        while (safe_poll(pfd, 1, 0) > 0 && n <= (sizeof(readbuffer) - 8)) {
                                 // read the rest of the ESC string
-                                int r = safe_read(0, readbuffer + n, MAX_LINELEN - n);
+                                int r = safe_read(0, readbuffer + n, sizeof(readbuffer) - n);
                                 if (r > 0)
                                         n += r;
                         }
@@ -2242,27 +2225,21 @@ static char readit(void)	// read (maybe cursor) key from stdin
 
                 for (eindex = esccmds; eindex < &esccmds[ESCCMDS_COUNT]; eindex++) {
                         int cnt = strnlen(eindex->seq, 4);
-
                         if (n <= cnt)
                                 continue;
-                        if (strncmp(eindex->seq, readbuffer + 1, cnt))
+                        if (strncmp(eindex->seq, readbuffer + 1, cnt) != 0)
                                 continue;
-                        // is a Cursor key- put derived value back into Q
-                        c = eindex->val;
-                        // for squeeze out the ESC sequence
-                        n = cnt + 1;
-                        break;
+                        c = eindex->val; // magic char value
+                        n = cnt + 1; // squeeze out the ESC sequence
+                        goto found;
                 }
-                if (eindex == &esccmds[ESCCMDS_COUNT]) {
-                        /* defined ESC sequence not found, set only one ESC */
-                        n = 1;
-        }
-        } else {
-                n = 1;
+                // defined ESC sequence not found
         }
+        n = 1;
+ found:
         // remove key sequence from Q
         chars_to_parse -= n;
-        memmove(readbuffer, readbuffer + n, MAX_LINELEN - n);
+        memmove(readbuffer, readbuffer + n, sizeof(readbuffer) - n);
         alarm(3);       // we are done waiting for input, turn alarm ON
         return c;
 }
@@ -2297,8 +2274,8 @@ static char get_one_char(void)
                 c = readit();   // get the users input
                 if (last_modifying_cmd != NULL) {
                         int len = strlen(last_modifying_cmd);
-                        if (len >= MAX_LINELEN - 1) {
-                                psbs("last_modifying_cmd overrun");
+                        if (len >= MAX_INPUT_LEN - 1) {
+                                status_line_bold("last_modifying_cmd overrun");
                         } else {
                                 // add new char to q
                                 last_modifying_cmd[len] = c;
@@ -2311,14 +2288,15 @@ static char get_one_char(void)
         return c;
 }
 
-static char *get_input_line(const char * prompt) // get input line- use "status line"
+// Get input line (uses "status line" area)
+static char *get_input_line(const char *prompt)
 {
-        static char *buf; // [MAX_LINELEN]
+        static char *buf; // [MAX_INPUT_LEN]
 
         char c;
         int i;
 
-        if (!buf) buf = xmalloc(MAX_LINELEN);
+        if (!buf) buf = xmalloc(MAX_INPUT_LEN);
 
         strcpy(buf, prompt);
         last_status_cksum = 0;  // force status update
@@ -2327,24 +2305,20 @@ static char *get_input_line(const char * prompt) // get input line- use "status
         write1(prompt);      // write out the :, /, or ? prompt
 
         i = strlen(buf);
-        while (i < MAX_LINELEN) {
-                c = get_one_char();     // read user input
+        while (i < MAX_INPUT_LEN) {
+                c = get_one_char();
                 if (c == '\n' || c == '\r' || c == 27)
-                        break;          // is this end of input
+                        break;          // this is end of input
                 if (c == erase_char || c == 8 || c == 127) {
                         // user wants to erase prev char
-                        i--;            // backup to prev char
-                        buf[i] = '\0';  // erase the char
-                        //buf[i + 1] = '\0';    // null terminate buffer
-                        write1("\b \b");     // erase char on screen
-                        if (i <= 0) {   // user backs up before b-o-l, exit
+                        buf[--i] = '\0';
+                        write1("\b \b"); // erase char on screen
+                        if (i <= 0) // user backs up before b-o-l, exit
                                 break;
-                        }
                 } else {
-                        buf[i] = c;     // save char in buffer
-                        buf[i + 1] = '\0';      // make sure buffer is null terminated
-                        bb_putchar(c);   // echo the char back to user
-                        i++;
+                        buf[i] = c;
+                        buf[++i] = '\0';
+                        bb_putchar(c);
                 }
         }
         refresh(FALSE);
@@ -2371,30 +2345,30 @@ static int file_insert(const char * fn, char *p
 
         /* Validate file */
         if (stat(fn, &statbuf) < 0) {
-                psbs("\"%s\" %s", fn, strerror(errno));
+                status_line_bold("\"%s\" %s", fn, strerror(errno));
                 goto fi0;
         }
         if ((statbuf.st_mode & S_IFREG) == 0) {
                 // This is not a regular file
-                psbs("\"%s\" Not a regular file", fn);
+                status_line_bold("\"%s\" Not a regular file", fn);
                 goto fi0;
         }
         /* // this check is done by open()
         if ((statbuf.st_mode & (S_IRUSR | S_IRGRP | S_IROTH)) == 0) {
                 // dont have any read permissions
-                psbs("\"%s\" Not readable", fn);
+                status_line_bold("\"%s\" Not readable", fn);
                 goto fi0;
         }
         */
         if (p < text || p > end) {
-                psbs("Trying to insert file outside of memory");
+                status_line_bold("Trying to insert file outside of memory");
                 goto fi0;
         }
 
         // read file to buffer
         fd = open(fn, O_RDONLY);
         if (fd < 0) {
-                psbs("\"%s\" %s", fn, strerror(errno));
+                status_line_bold("\"%s\" %s", fn, strerror(errno));
                 goto fi0;
         }
         size = statbuf.st_size;
@@ -2403,12 +2377,12 @@ static int file_insert(const char * fn, char *p
                 goto fi0;
         cnt = safe_read(fd, p, size);
         if (cnt < 0) {
-                psbs("\"%s\" %s", fn, strerror(errno));
+                status_line_bold("\"%s\" %s", fn, strerror(errno));
                 p = text_hole_delete(p, p + size - 1);  // un-do buffer insert
         } else if (cnt < size) {
                 // There was a partial read, shrink unused space text[]
                 p = text_hole_delete(p + cnt, p + (size - cnt) - 1);    // un-do buffer insert
-                psbs("cannot read all of file \"%s\"", fn);
+                status_line_bold("cannot read all of file \"%s\"", fn);
         }
         if (cnt >= size)
                 file_modified++;
@@ -2434,7 +2408,7 @@ static int file_write(char * fn, char * first, char * last)
         int fd, cnt, charcnt;
 
         if (fn == 0) {
-                psbs("No current filename");
+                status_line_bold("No current filename");
                 return -2;
         }
         charcnt = 0;
@@ -2467,7 +2441,7 @@ static int file_write(char * fn, char * first, char * last)
 //----- Move the cursor to row x col (count from 0, not 1) -------
 static void place_cursor(int row, int col, int optimize)
 {
-        char cm1[32];
+        char cm1[sizeof(CMrc) + sizeof(int)*3 * 2];
         char *cm;
 
         if (row < 0) row = 0;
@@ -2481,9 +2455,18 @@ static void place_cursor(int row, int col, int optimize)
 
 #if ENABLE_FEATURE_VI_OPTIMIZE_CURSOR
         if (optimize && col < 16) {
-                char cm2[MAX_LINELEN]; // better size estimate?
+                enum {
+                        SZ_UP = sizeof(CMup),
+                        SZ_DN = sizeof(CMdown),
+                        SEQ_SIZE = SZ_UP > SZ_DN ? SZ_UP : SZ_DN,
+                };
+                char cm2[SEQ_SIZE * 5 + 32]; // bigger than worst case size
                 char *screenp;
                 int Rrow = last_row;
+                int diff = Rrow - row;
+
+                if (diff < -5 || diff > 5)
+                        goto skip;
 
                 //----- find the minimum # of chars to move cursor -------------
                 //----- 2.  Try moving with discreet chars (Newline, [back]space, ...)
@@ -2511,9 +2494,11 @@ static void place_cursor(int row, int col, int optimize)
                 if (strlen(cm2) < strlen(cm)) {
                         cm = cm2;
                 }
+ skip: ;
         }
 #endif /* FEATURE_VI_OPTIMIZE_CURSOR */
         write1(cm);
+        last_row = row;
 }
 
 //----- Erase from cursor to end of line -----------------------
@@ -2592,7 +2577,7 @@ static void show_status_line(void)
                 cksum = bufsum(status_buffer, cnt);
         }
         if (have_status_msg || ((cnt > 0 && last_status_cksum != cksum))) {
-                last_status_cksum= cksum;               // remember if we have seen this line
+                last_status_cksum = cksum;              // remember if we have seen this line
                 place_cursor(rows - 1, 0, FALSE);       // put cursor on status line
                 write1(status_buffer);
                 clear_to_eol();
@@ -2611,13 +2596,13 @@ static void show_status_line(void)
 
 //----- format the status buffer, the bottom line of screen ------
 // format status buffer, with STANDOUT mode
-static void psbs(const char *format, ...)
+static void status_line_bold(const char *format, ...)
 {
         va_list args;
 
         va_start(args, format);
         strcpy(status_buffer, SOs);     // Terminal standout mode on
-        vsprintf(status_buffer + strlen(status_buffer), format, args);
+        vsprintf(status_buffer + sizeof(SOs)-1, format, args);
         strcat(status_buffer, SOn);     // Terminal standout mode off
         va_end(args);
 
@@ -2625,7 +2610,7 @@ static void psbs(const char *format, ...)
 }
 
 // format status buffer
-static void psb(const char *format, ...)
+static void status_line(const char *format, ...)
 {
         va_list args;
 
@@ -2636,15 +2621,53 @@ static void psb(const char *format, ...)
         have_status_msg = 1;
 }
 
-static void ni(const char * s) // display messages
+// copy s to buf, convert unprintable
+static void print_literal(char *buf, const char *s)
 {
-        char buf[MAX_LINELEN];
+        unsigned char c;
+        char b[2];
+
+        b[1] = '\0';
+        buf[0] = '\0';
+        if (!s[0])
+                s = "(NULL)";
+        for (; *s; s++) {
+                int c_is_no_print;
+
+                c = *s;
+                c_is_no_print = (c & 0x80) && !Isprint(c);
+                if (c_is_no_print) {
+                        strcat(buf, SOn);
+                        c = '.';
+                }
+                if (c < ' ' || c == 127) {
+                        strcat(buf, "^");
+                        if (c == 127)
+                                c = '?';
+                        else
+                                c += '@';
+                }
+                b[0] = c;
+                strcat(buf, b);
+                if (c_is_no_print)
+                        strcat(buf, SOs);
+                if (*s == '\n')
+                        strcat(buf, "$");
+                if (strlen(buf) > MAX_INPUT_LEN - 10) // paranoia
+                        break;
+        }
+}
+
+static void not_implemented(const char *s)
+{
+        char buf[MAX_INPUT_LEN];
 
         print_literal(buf, s);
-        psbs("\'%s\' is not implemented", buf);
+        status_line_bold("\'%s\' is not implemented", buf);
 }
 
-static int format_edit_status(void)     // show file status on status line
+// show file status on status line
+static int format_edit_status(void)
 {
         static int tot;
         static const char cmd_mode_indicator[] ALIGN1 = "-IR-";
@@ -2714,67 +2737,57 @@ static void redraw(int full_screen)
 //----- Format a text[] line into a buffer ---------------------
 // Returns number of leading chars which should be ignored
 // (return value is always <= offset)
-static int format_line(char *dest, char *src, int li)
+static char* format_line(char *src, int li)
 {
         char c;
         int co;
         int ofs = offset;
+        char *dest = scr_out_buf; // [MAX_SCR_COLS + MAX_TABSTOP * 2]
 
-        memset(dest, ' ', MAX_SCR_COLS);
-        for (co = 0; co < MAX_SCR_COLS; co++) {
-                c = ' ';                // assume blank
-                if (li > 0 && co == 0) {
-                        c = '~';        // not first line, assume Tilde
-                }
+        memset(dest, ' ', MAX_SCR_COLS + MAX_TABSTOP * 2);
+
+        c = '~'; // char in col 0 in non-existent lines is '~'
+        for (co = 0; co < MAX_SCR_COLS + MAX_TABSTOP; co++) {
                 // are there chars in text[] and have we gone past the end
-                if (text < end && src < end) {
+                if (src < end) {
                         c = *src++;
-
                         if (c == '\n')
                                 break;
                         if ((c & 0x80) && !Isprint(c)) {
                                 c = '.';
                         }
-                        if ((unsigned char)(c) < ' ' || c == 0x7f) {
+                        if ((unsigned char)c < ' ' || c == 0x7f) {
                                 if (c == '\t') {
                                         c = ' ';
                                         //      co %    8     !=     7
                                         while ((co % tabstop) != (tabstop - 1)) {
                                                 dest[co++] = c;
-                                                if (co >= MAX_SCR_COLS)
-                                                        goto ret;
                                         }
                                 } else {
                                         dest[co++] = '^';
-                                        if (co >= MAX_SCR_COLS)
-                                                goto ret;
                                         if (c == 0x7f)
                                                 c = '?';
                                         else
-                                                c += '@';       // make it visible
+                                                c += '@'; // Ctrl-X -> 'X'
                                 }
                         }
                 }
-                // the co++ is done here so that the column will
-                // not be overwritten when we blank-out the rest of line
                 dest[co] = c;
-                // discard scrolled-off portion, in tabstop-sized pieces
+                // discard scrolled-off-to-the-left portion,
+                // in tabstop-sized pieces
                 if (ofs >= tabstop && co >= tabstop) {
+                        memmove(dest, dest + tabstop, co + 1);
                         co -= tabstop;
                         ofs -= tabstop;
-                        memset(&dest[co + 1], ' ', tabstop);
                 }
                 if (src >= end)
                         break;
         }
- ret:
-        if (co < ofs) {
-                // entire line has scrolled off, make it entirely blank
-                memset(dest, ' ', MAX_SCR_COLS);
-                ofs = 0;
-        }
-        dest[MAX_SCR_COLS-1] = '\0';
-        return ofs;
+        // check "short line, gigantic offset" case
+        if (co < ofs)
+                ofs = co + 1;
+        dest[ofs + MAX_SCR_COLS] = '\0';
+        return &dest[ofs];
 }
 
 //----- Refresh the changed screen lines -----------------------
@@ -2787,29 +2800,29 @@ static void refresh(int full_screen)
         static int old_offset;
 
         int li, changed;
-        char buf[MAX_SCR_COLS];
         char *tp, *sp;          // pointer into text[] and screen[]
-#if ENABLE_FEATURE_VI_OPTIMIZE_CURSOR
-        int last_li = -2; // last line that changed- for optimizing cursor movement
-#endif
 
-        if (ENABLE_FEATURE_VI_WIN_RESIZE)
+        if (ENABLE_FEATURE_VI_WIN_RESIZE) {
+                int c = columns, r = rows;
                 get_terminal_width_height(0, &columns, &rows);
+                if (rows > MAX_SCR_ROWS) rows = MAX_SCR_ROWS;
+                if (columns > MAX_SCR_COLS) columns = MAX_SCR_COLS;
+                full_screen |= (c - columns) | (r - rows);
+        }
         sync_cursor(dot, &crow, &ccol); // where cursor will be (on "dot")
         tp = screenbegin;       // index into text[] of top line
 
         // compare text[] to screen[] and mark screen[] lines that need updating
         for (li = 0; li < rows - 1; li++) {
-                int ofs;
                 int cs, ce;                             // column start & end
-                // format current text line into buf
-                ofs = format_line(buf, tp, li);
+                // format current text line
+                char *out_buf = format_line(tp, li);
 
                 // skip to the end of the current text[] line
                 while (tp < end && *tp++ != '\n')
                         continue;
 
-                // see if there are any changes between vitual screen and buf
+                // see if there are any changes between vitual screen and out_buf
                 changed = FALSE;        // assume no change
                 cs = 0;
                 ce = columns - 1;
@@ -2821,15 +2834,15 @@ static void refresh(int full_screen)
                 // compare newly formatted buffer with virtual screen
                 // look forward for first difference between buf and screen
                 for (; cs <= ce; cs++) {
-                        if (buf[cs + ofs] != sp[cs]) {
+                        if (out_buf[cs] != sp[cs]) {
                                 changed = TRUE; // mark for redraw
                                 break;
                         }
                 }
 
-                // look backward for last difference between buf and screen
+                // look backward for last difference between out_buf and screen
                 for (; ce >= cs; ce--) {
-                        if (buf[ce + ofs] != sp[ce]) {
+                        if (out_buf[ce] != sp[ce]) {
                                 changed = TRUE; // mark for redraw
                                 break;
                         }
@@ -2846,50 +2859,26 @@ static void refresh(int full_screen)
                 if (cs < 0) cs = 0;
                 if (ce > columns - 1) ce = columns - 1;
                 if (cs > ce) { cs = 0; ce = columns - 1; }
-                // is there a change between vitual screen and buf
+                // is there a change between vitual screen and out_buf
                 if (changed) {
                         // copy changed part of buffer to virtual screen
-                        memmove(sp+cs, buf+(cs+ofs), ce-cs+1);
+                        memcpy(sp+cs, out_buf+cs, ce-cs+1);
 
                         // move cursor to column of first change
-                        if (offset != old_offset) {
-                                // opti_cur_move is still too stupid
-                                // to handle offsets correctly
-                                place_cursor(li, cs, FALSE);
-                        } else {
-#if ENABLE_FEATURE_VI_OPTIMIZE_CURSOR
-                                // if this just the next line
-                                //  try to optimize cursor movement
-                                //  otherwise, use standard ESC sequence
-                                place_cursor(li, cs, li == (last_li+1) ? TRUE : FALSE);
-                                last_li = li;
-#else
-                                place_cursor(li, cs, FALSE);    // use standard ESC sequence
-#endif /* FEATURE_VI_OPTIMIZE_CURSOR */
-                        }
+                        //if (offset != old_offset) {
+                        //      // place_cursor is still too stupid
+                        //      // to handle offsets correctly
+                        //      place_cursor(li, cs, FALSE);
+                        //} else {
+                                place_cursor(li, cs, TRUE);
+                        //}
 
                         // write line out to terminal
-                        {
-                                int nic = ce - cs + 1;
-                                char *out = sp + cs;
-
-                                while (--nic >= 0) {
-                                        bb_putchar(*out);
-                                        out++;
-                                }
-                        }
-#if ENABLE_FEATURE_VI_OPTIMIZE_CURSOR
-                        last_row = li;
-#endif
+                        fwrite(&sp[cs], ce - cs + 1, 1, stdout);
                 }
         }
 
-#if ENABLE_FEATURE_VI_OPTIMIZE_CURSOR
-        place_cursor(crow, ccol, (crow == last_row) ? TRUE : FALSE);
-        last_row = crow;
-#else
-        place_cursor(crow, ccol, FALSE);
-#endif
+        place_cursor(crow, ccol, TRUE);
 
         old_offset = offset;
 }
@@ -2919,13 +2908,14 @@ static void refresh(int full_screen)
 static void do_cmd(char c)
 {
         const char *msg;
-        char c1, *p, *q, buf[9], *save_dot;
+        char c1, *p, *q, *save_dot;
+        char buf[12];
         int cnt, i, j, dir, yf;
 
-        c1 = c;                         // quiet the compiler
-        cnt = yf = dir = 0;     // quiet the compiler
-        msg = p = q = save_dot = buf;   // quiet the compiler
-        memset(buf, '\0', 9);   // clear buf
+//      c1 = c;                         // quiet the compiler
+//      cnt = yf = dir = 0;     // quiet the compiler
+//      msg = p = q = save_dot = buf;   // quiet the compiler
+        memset(buf, '\0', 12);
 
         show_status_line();
 
@@ -3022,7 +3012,7 @@ static void do_cmd(char c)
                         buf[1] = c + '@';
                         buf[2] = '\0';
                 }
-                ni(buf);
+                not_implemented(buf);
                 end_cmd_q();    // stop adding to q
         case 0x00:                      // nul- ignore
                 break;
@@ -3156,7 +3146,7 @@ static void do_cmd(char c)
         case 'p':                       // p- put register after
                 p = reg[YDreg];
                 if (p == 0) {
-                        psbs("Nothing in register %c", what_reg());
+                        status_line_bold("Nothing in register %c", what_reg());
                         break;
                 }
                 // are we putting whole lines or strings
@@ -3319,7 +3309,7 @@ static void do_cmd(char c)
                 }
  dc2:
                 if (*msg)
-                        psbs("%s", msg);
+                        status_line_bold("%s", msg);
                 break;
         case '{':                       // {- move backward paragraph
                 q = char_search(dot, "\n\n", BACK, FULL);
@@ -3364,7 +3354,7 @@ static void do_cmd(char c)
                  || strncasecmp(p, "q!", cnt) == 0   // delete lines
                 ) {
                         if (file_modified && p[1] != '!') {
-                                psbs("No write since last change (:quit! overrides)");
+                                status_line_bold("No write since last change (:quit! overrides)");
                         } else {
                                 editing = 0;
                         }
@@ -3376,11 +3366,11 @@ static void do_cmd(char c)
                         cnt = file_write(current_filename, text, end - 1);
                         if (cnt < 0) {
                                 if (cnt == -1)
-                                        psbs("Write error: %s", strerror(errno));
+                                        status_line_bold("Write error: %s", strerror(errno));
                         } else {
                                 file_modified = 0;
                                 last_file_modified = -1;
-                                psb("\"%s\" %dL, %dC", current_filename, count_lines(text, end - 1), cnt);
+                                status_line("\"%s\" %dL, %dC", current_filename, count_lines(text, end - 1), cnt);
                                 if (p[0] == 'x' || p[1] == 'q' || p[1] == 'n'
                                  || p[0] == 'X' || p[1] == 'Q' || p[1] == 'N'
                                 ) {
@@ -3393,7 +3383,7 @@ static void do_cmd(char c)
                         dot = find_line(j);             // go to line # j
                         dot_skip_over_ws();
                 } else {                // unrecognised cmd
-                        ni(p);
+                        not_implemented(p);
                 }
 #endif /* !FEATURE_VI_COLON */
                 break;
@@ -3539,6 +3529,9 @@ static void do_cmd(char c)
  dc5:
                 cmd_mode = 2;
                 break;
+        case VI_K_DELETE:
+                c = 'x';
+                // fall through
         case 'X':                       // X- delete char before dot
         case 'x':                       // x- delete the current char
         case 's':                       // s- substitute the current char
@@ -3566,13 +3559,13 @@ static void do_cmd(char c)
                 }
                 if (file_modified) {
                         if (ENABLE_FEATURE_VI_READONLY && readonly_mode) {
-                                psbs("\"%s\" File is read only", current_filename);
+                                status_line_bold("\"%s\" File is read only", current_filename);
                                 break;
                         }
                         cnt = file_write(current_filename, text, end - 1);
                         if (cnt < 0) {
                                 if (cnt == -1)
-                                        psbs("Write error: %s", strerror(errno));
+                                        status_line_bold("Write error: %s", strerror(errno));
                         } else if (cnt == (end - 1 - text + 1)) {
                                 editing = 0;
                         }
@@ -3671,7 +3664,7 @@ static void do_cmd(char c)
                                 if (*p == '\n')
                                         cnt++;
                         }
-                        psb("%s %d lines (%d chars) using [%c]",
+                        status_line("%s %d lines (%d chars) using [%c]",
                                 buf, cnt, strlen(reg[YDreg]), what_reg());
 #endif
                         end_cmd_q();    // stop adding to q
@@ -3793,15 +3786,15 @@ static int Ip = 97;             // Insert command Probability
 static int Yp = 98;             // Yank command Probability
 static int Pp = 99;             // Put command Probability
 static int M = 0, N = 0, I = 0, D = 0, Y = 0, P = 0, U = 0;
-const char chars[20] = "\t012345 abcdABCD-=.$";
-const char *const words[20] = {
+static const char chars[20] = "\t012345 abcdABCD-=.$";
+static const char *const words[20] = {
         "this", "is", "a", "test",
         "broadcast", "the", "emergency", "of",
         "system", "quick", "brown", "fox",
         "jumped", "over", "lazy", "dogs",
         "back", "January", "Febuary", "March"
 };
-const char *const lines[20] = {
+static const char *const lines[20] = {
         "You should have received a copy of the GNU General Public License\n",
         "char c, cm, *cmd, *cmd1;\n",
         "generate a command by percentages\n",
@@ -3823,7 +3816,7 @@ const char *const lines[20] = {
         "The last command will be automatically run.\n",
         "This is too much english for a computer geek.\n",
 };
-char *multilines[20] = {
+static char *multilines[20] = {
         "You should have received a copy of the GNU General Public License\n",
         "char c, cm, *cmd, *cmd1;\n",
         "generate a command by percentages\n",
@@ -3862,7 +3855,7 @@ static void crash_dummy()
  cd0:
         startrbi = rbi = 0;
         sleeptime = 0;          // how long to pause between commands
-        memset(readbuffer, '\0', MAX_LINELEN);   // clear the read buffer
+        memset(readbuffer, '\0', sizeof(readbuffer));
         // generate a command by percentages
         percent = (int) lrand48() % 100;        // get a number from 0-99
         if (percent < Mp) {     //  Movement commands
@@ -3947,7 +3940,7 @@ static void crash_test()
         static time_t oldtim;
 
         time_t tim;
-        char d[2], msg[MAX_LINELEN];
+        char d[2], msg[80];
 
         msg[0] = '\0';
         if (end < text) {
@@ -3980,7 +3973,7 @@ static void crash_test()
                 }
                 alarm(3);
         }
-        tim = (time_t) time((time_t *) 0);
+        tim = time(NULL);
         if (tim >= (oldtim + 3)) {
                 sprintf(status_buffer,
                                 "Tot=%d: M=%d N=%d I=%d D=%d Y=%d P=%d U=%d size=%d",