34 files changed, 319 insertions, 238 deletions

diff --git a/archival/dpkg.c b/archival/dpkg.c
index a6a8333a8..a53da8df1 100644
--- a/archival/dpkg.c
+++ b/archival/dpkg.c
@@ -1694,7 +1694,7 @@ static void unpack_package(deb_file_t *deb_file)
         accept_list = NULL;
         i = 0;
         while (i < ARRAY_SIZE(all_control_files)) {
-                char *c = xasprintf("./%s", all_control_files[i]);
+                char *c = concat_path_file(".", all_control_files[i]);
                 llist_add_to(&accept_list, c);
                 i++;
         }
diff --git a/archival/libarchive/lzo1x_9x.c b/archival/libarchive/lzo1x_9x.c
index df26b375f..2c405b636 100644
--- a/archival/libarchive/lzo1x_9x.c
+++ b/archival/libarchive/lzo1x_9x.c
@@ -797,7 +797,6 @@ static int lzo1x_999_compress_internal(const uint8_t *in, unsigned in_len,
                 if (swd->use_best_off)
                         better_match(swd, &m_len, &m_off);
 #endif
-
                 /* shall we try a lazy match ? */
                 ahead = 0;
                 if (m_len >= max_lazy) {
@@ -811,7 +810,6 @@ static int lzo1x_999_compress_internal(const uint8_t *in, unsigned in_len,
                         max_ahead = LZO_MIN(2, (unsigned)l1 - 1);
                 }
 
-
                 while (ahead < max_ahead && c->look > m_len) {
                         int lazy_match_min_gain;
 
diff --git a/archival/lzop.c b/archival/lzop.c
index bdcc6d548..98587e8dd 100644
--- a/archival/lzop.c
+++ b/archival/lzop.c
@@ -208,7 +208,6 @@ static NOINLINE int lzo1x_optimize(uint8_t *in, unsigned in_len,
                 lit = 0;
                 goto match_done;
 
-
                 /* handle matches */
                 do {
                         if (t < 16) { /* a M1 match */
diff --git a/coreutils/factor.c b/coreutils/factor.c
index 9de5ea8eb..1889836b0 100644
--- a/coreutils/factor.c
+++ b/coreutils/factor.c
@@ -136,7 +136,7 @@ static void factorize(wide_t N);
 
 static half_t isqrt_odd(wide_t N)
 {
-        half_t s = isqrt(N);
+        half_t s = isqrt_ull(N);
         /* s^2 is <= N, (s+1)^2 > N */
 
         /* If s^2 in fact is EQUAL to N, it's very lucky.
diff --git a/editors/sed.c b/editors/sed.c
index 204417108..b9e2c40ad 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -668,9 +668,8 @@ static void add_cmd(const char *cmdstr)
 
         /* Append this line to any unfinished line from last time. */
         if (G.add_cmd_line) {
-                char *tp = xasprintf("%s\n%s", G.add_cmd_line, cmdstr);
-                free(G.add_cmd_line);
-                cmdstr = G.add_cmd_line = tp;
+                cmdstr = xasprintf_inplace(G.add_cmd_line,
+                        "%s\n%s", G.add_cmd_line, cmdstr);
         }
 
         /* If this line ends with unescaped backslash, request next line. */
diff --git a/editors/vi.c b/editors/vi.c
index 7ec3427f9..e3ad120f6 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -612,7 +612,6 @@ static int crashme = 0;
 #endif
 
 static void show_status_line(void);     // put a message on the bottom line
-static void status_line_bold(const char *, ...);
 
 static void show_help(void)
 {
@@ -1172,11 +1171,15 @@ static void redraw(int full_screen)
 //----- Flash the screen  --------------------------------------
 static void flash(int h)
 {
-        standout_start();
-        redraw(TRUE);
+        //standout_start();
+        //redraw(TRUE);
+        write1(ESC"[?5h"); // "reverse screen on"
+
         mysleep(h);
-        standout_end();
-        redraw(TRUE);
+
+        //standout_end();
+        //redraw(TRUE);
+        write1(ESC"[?5l"); // "reverse screen off"
 }
 
 static void indicate_error(void)
@@ -1411,11 +1414,10 @@ static void show_status_line(void)
                 go_bottom_and_clear_to_eol();
                 write1(status_buffer);
                 if (have_status_msg) {
-                        if (((int)strlen(status_buffer) - (have_status_msg - 1)) >
-                                        (columns - 1) ) {
-                                have_status_msg = 0;
+                        int n = (int)strlen(status_buffer) - (have_status_msg - 1);
+                        // careful with int->unsigned promotion in comparison!
+                        if (n >= 0 && n >= columns)
                                 Hit_Return();
-                        }
                         have_status_msg = 0;
                 }
                 place_cursor(crow, ccol);  // put cursor back in correct place
@@ -2725,7 +2727,7 @@ static char *get_one_address(char *p, int *result, int *valid)
 
 // Read line addresses for a colon command.  The user can enter as
 // many as they like but only the last two will be used.
-static char *get_address(char *p, int *b, int *e, unsigned int *got)
+static char *get_address(char *p, int *b, int *e, unsigned *got)
 {
         int state = GET_ADDRESS;
         int valid;
@@ -2839,19 +2841,23 @@ static void setops(char *args, int flg_no)
 # if ENABLE_FEATURE_VI_COLON_EXPAND
 static char *expand_args(char *args)
 {
-        char *s, *t;
+        char *s;
         const char *replace;
 
         args = xstrdup(args);
         for (s = args; *s; s++) {
+                unsigned n;
+
                 if (*s == '%') {
                         replace = current_filename;
                 } else if (*s == '#') {
                         replace = alt_filename;
                 } else {
                         if (*s == '\\' && s[1] != '\0') {
-                                for (t = s++; *t; t++)
+                                char *t;
+                                for (t = s; *t; t++)
                                         *t = t[1];
+                                s++;
                         }
                         continue;
                 }
@@ -2862,11 +2868,9 @@ static char *expand_args(char *args)
                         return NULL;
                 }
 
-                *s = '\0';
-                t = xasprintf("%s%s%s", args, replace, s+1);
-                s = t + (s - args) + strlen(replace);
-                free(args);
-                args = t;
+                n = (s - args);
+                xasprintf_inplace(args, "%.*s%s%s", n, args, replace, s+1);
+                s = args + n + strlen(replace);
         }
         return args;
 }
@@ -2944,7 +2948,6 @@ static char *regex_search(char *q, regex_t *preg, const char *Rorig,
 # define strchr_backslash(s, c) strchr(s, c)
 #endif /* ENABLE_FEATURE_VI_REGEX_SEARCH */
 
-// buf must be no longer than MAX_INPUT_LEN!
 static void colon(char *buf)
 {
 #if !ENABLE_FEATURE_VI_COLON
@@ -3004,16 +3007,17 @@ static void colon(char *buf)
         }
         not_implemented(p);
 #else
-
+        char cmd[sizeof("features!")]; // longest known command + NUL
+        char *args;
+        int cmdlen;
+        char *useforce;
+        char *q, *r;
+        int b, e;
 // check how many addresses we got
 # define GOT_ADDRESS (got & 1)
-# define GOT_RANGE ((got & 3) == 3)
-
-        char c, *buf1, *q, *r;
-        char *fn, cmd[MAX_INPUT_LEN], *cmdend, *args, *exp = NULL;
-        int i, l, li, b, e;
-        unsigned int got;
-        int useforce;
+# define GOT_RANGE   ((got & 3) == 3)
+        unsigned got;
+        char *exp = NULL; // may hold expand_args() result: if VI_COLON_EXPAND, needs freeing!
 
         // :3154        // if (-e line 3154) goto it  else stay put
         // :4,33w! foo  // write a portion of buffer to file "foo"
@@ -3028,52 +3032,38 @@ static void colon(char *buf)
         // :/xyz/       // goto the "xyz" line
         // :s/find/replace/ // substitute pattern "find" with "replace"
         // :!<cmd>      // run <cmd> then return
-        //
 
         while (*buf == ':')
                 buf++;                  // move past leading colons
-        while (isblank(*buf))
-                buf++;                  // move past leading blanks
-        if (!buf[0] || buf[0] == '"')
+        buf = skip_whitespace(buf);     // move past leading blanks
+        if (!*buf || *buf == '"')
                 goto ret;               // ignore empty lines or those starting with '"'
 
-        li = i = 0;
+        // look for optional address(es)  ":." ":1" ":1,9" ":'q,'a" ":%"
         b = e = -1;
         got = 0;
-        li = count_lines(text, end - 1);
-        fn = current_filename;
-
-        // look for optional address(es)  :.  :1  :1,9   :'q,'a   :%
         buf = get_address(buf, &b, &e, &got);
-        if (buf == NULL) {
+        if (buf == NULL)
                 goto ret;
-        }
 
         // get the COMMAND into cmd[]
-        strcpy(cmd, buf);
-        buf1 = cmd;
-        while (!isspace(*buf1) && *buf1 != '\0') {
-                buf1++;
-        }
-        cmdend = buf1;
-        // get any ARGuments
-        while (isblank(*buf1))
-                buf1++;
-        args = buf1;
-        *cmdend = '\0';
-        useforce = FALSE;
-        if (cmdend > cmd && cmdend[-1] == '!') {
-                useforce = TRUE;
-                cmdend[-1] = '\0';   // get rid of !
-        }
+        safe_strncpy(cmd, buf, sizeof(cmd));
+        skip_non_whitespace(cmd)[0] = '\0';
+        useforce = last_char_is(cmd, '!');
+        if (useforce && useforce > cmd)
+                *useforce = '\0';   // "CMD!" -> "CMD" (unless single "!")
+        // find ARGuments
+        args = skip_whitespace(skip_non_whitespace(buf));
+
         // assume the command will want a range, certain commands
         // (read, substitute) need to adjust these assumptions
-        if (!GOT_ADDRESS) {
-                q = text;                       // no addr, use 1,$ for the range
-                r = end - 1;
-        } else {
-                // at least one addr was given, get its details
-                if (e < 0 || e > li) {
+        q = text;          // if no addr, use 1,$ for the range
+        r = end - 1;
+        if (GOT_ADDRESS) { // at least one addr was given, get its details
+                int lines;
+                if (e < 0
+                 || e > (lines = count_lines(text, end - 1))
+                ) {
                         status_line_bold("Invalid range");
                         goto ret;
                 }
@@ -3083,31 +3073,28 @@ static void colon(char *buf)
                         // number of the single line the user wants.
                         // Reset the end pointer to the end of that line.
                         r = end_line(q);
-                        li = 1;
                 } else {
                         // we were given two addrs.  change the
                         // start pointer to the addr given by user.
-                        if (b < 0 || b > li || b > e) {
+                        if (b < 0 || b > lines || b > e) {
                                 status_line_bold("Invalid range");
                                 goto ret;
                         }
                         q = find_line(b);       // what line is #b
                         r = end_line(r);
-                        li = e - b + 1;
                 }
         }
         // ------------ now look for the command ------------
-        i = strlen(cmd);
-        if (i == 0) {           // :123CR goto line #123
+        cmdlen = strlen(cmd);
+        if (cmdlen == 0) {      // ":123<enter>" - goto line #123
                 if (e >= 0) {
                         dot = find_line(e);     // what line is #e
                         dot_skip_over_ws();
                 }
         }
 # if ENABLE_FEATURE_ALLOW_EXEC
-        else if (cmd[0] == '!') {       // run a cmd
+        else if (cmd[0] == '!') {       // ":!CMD" - run shell CMD
                 int retcode;
-                // :!ls   run the <cmd>
                 if (GOT_ADDRESS) {
                         status_line_bold("Range not allowed");
                         goto ret;
@@ -3129,25 +3116,27 @@ static void colon(char *buf)
                         e = count_lines(text, dot);
                 }
                 status_line("%d", e);
-        } else if (strncmp(cmd, "delete", i) == 0) {    // delete lines
+        } else if (strncmp(cmd, "delete", cmdlen) == 0) {       // delete lines
                 if (!GOT_ADDRESS) {     // no addr given- use defaults
                         q = begin_line(dot);    // assume .,. for the range
                         r = end_line(dot);
                 }
                 dot = yank_delete(q, r, WHOLE, YANKDEL, ALLOW_UNDO);    // save, then delete lines
                 dot_skip_over_ws();
-        } else if (strncmp(cmd, "edit", i) == 0) {      // Edit a file
+        } else if (strncmp(cmd, "edit", cmdlen) == 0) { // Edit a file
                 int size;
+                char *fn;
 
                 // don't edit, if the current file has been modified
                 if (modified_count && !useforce) {
                         status_line_bold("No write since last change (:%s! overrides)", cmd);
                         goto ret;
                 }
+                fn = current_filename;
                 if (args[0]) {
                         // the user supplied a file name
-                        fn = exp = expand_args(args);
-                        if (exp == NULL)
+                        fn = expand_args(args);
+                        if (fn == NULL)
                                 goto ret;
                 } else if (current_filename == NULL) {
                         // no user file name, no current name- punt
@@ -3167,8 +3156,6 @@ static void colon(char *buf)
                         reg[YDreg] = NULL;
                 }
 # endif
-                // how many lines in text[]?
-                li = count_lines(text, end - 1);
                 status_line("'%s'%s"
                         IF_FEATURE_VI_READONLY("%s")
                         " %uL, %uC",
@@ -3177,9 +3164,10 @@ static void colon(char *buf)
                         IF_FEATURE_VI_READONLY(
                                 ((readonly_mode) ? " [Readonly]" : ""),
                         )
-                        li, (int)(end - text)
+                        count_lines(text, end - 1),
+                        (int)(end - text)
                 );
-        } else if (strncmp(cmd, "file", i) == 0) {      // what File is this
+        } else if (strncmp(cmd, "file", cmdlen) == 0) { // what File is this
                 if (e >= 0) {
                         status_line_bold("No address allowed on this command");
                         goto ret;
@@ -3194,46 +3182,52 @@ static void colon(char *buf)
                         // user wants file status info
                         last_status_cksum = 0;  // force status update
                 }
-        } else if (strncmp(cmd, "features", i) == 0) {  // what features are available
+        } else if (strncmp(cmd, "features", cmdlen) == 0) {     // what features are available
                 // print out values of all features
                 go_bottom_and_clear_to_eol();
                 cookmode();
                 show_help();
                 rawmode();
                 Hit_Return();
-        } else if (strncmp(cmd, "list", i) == 0) {      // literal print line
+        } else if (strncmp(cmd, "list", cmdlen) == 0) { // literal print line
+                char *dst;
                 if (!GOT_ADDRESS) {     // no addr given- use defaults
                         q = begin_line(dot);    // assume .,. for the range
                         r = end_line(dot);
                 }
-                go_bottom_and_clear_to_eol();
-                puts("\r");
-                for (; q <= r; q++) {
+                have_status_msg = 1;
+                dst = status_buffer;
+#define MAXPRINT (sizeof(ESC_BOLD_TEXT "^?" ESC_NORM_TEXT) + 1)
+                while (q <= r && dst < status_buffer + STATUS_BUFFER_LEN - MAXPRINT) {
+                        char c;
                         int c_is_no_print;
 
-                        c = *q;
+                        c = *q++;
+                        if (c == '\n') {
+                                *dst++ = '$';
+                                break;
+                        }
                         c_is_no_print = (c & 0x80) && !Isprint(c);
                         if (c_is_no_print) {
-                                c = '.';
-                                standout_start();
+//TODO: print fewer ESC if more than one ctrl char
+                                dst = stpcpy(dst, ESC_BOLD_TEXT);
+                                *dst++ = '.';
+                                dst = stpcpy(dst, ESC_NORM_TEXT);
+                                continue;
                         }
-                        if (c == '\n') {
-                                write1("$\r");
-                        } else if (c < ' ' || c == 127) {
-                                bb_putchar('^');
+                        if (c < ' ' || c == 127) {
+                                *dst++ = '^';
                                 if (c == 127)
                                         c = '?';
                                 else
                                         c += '@';
                         }
-                        bb_putchar(c);
-                        if (c_is_no_print)
-                                standout_end();
+                        *dst++ = c;
                 }
-                Hit_Return();
-        } else if (strncmp(cmd, "quit", i) == 0 // quit
-                || strncmp(cmd, "next", i) == 0 // edit next file
-                || strncmp(cmd, "prev", i) == 0 // edit previous file
+                *dst = '\0';
+        } else if (strncmp(cmd, "quit", cmdlen) == 0 // quit
+                || strncmp(cmd, "next", cmdlen) == 0 // edit next file
+                || strncmp(cmd, "prev", cmdlen) == 0 // edit previous file
         ) {
                 int n;
                 if (useforce) {
@@ -3268,13 +3262,14 @@ static void colon(char *buf)
                         optind -= 2;
                 }
                 editing = 0;
-        } else if (strncmp(cmd, "read", i) == 0) {      // read file into text[]
+        } else if (strncmp(cmd, "read", cmdlen) == 0) { // read file into text[]
                 int size, num;
+                char *fn = current_filename;
 
                 if (args[0]) {
                         // the user supplied a file name
-                        fn = exp = expand_args(args);
-                        if (exp == NULL)
+                        fn = expand_args(args);
+                        if (fn == NULL)
                                 goto ret;
                         init_filename(fn);
                 } else if (current_filename == NULL) {
@@ -3300,17 +3295,16 @@ static void colon(char *buf)
                 }
                 if (size < 0)
                         goto ret;       // nothing was inserted
-                // how many lines in text[]?
-                li = count_lines(q, q + size - 1);
                 status_line("'%s'"
                         IF_FEATURE_VI_READONLY("%s")
                         " %uL, %uC",
                         fn,
                         IF_FEATURE_VI_READONLY((readonly_mode ? " [Readonly]" : ""),)
-                        li, size
+                        count_lines(q, q + size - 1),
+                        size
                 );
                 dot = find_line(num);
-        } else if (strncmp(cmd, "rewind", i) == 0) {    // rewind cmd line args
+        } else if (strncmp(cmd, "rewind", cmdlen) == 0) {       // rewind cmd line args
                 if (modified_count && !useforce) {
                         status_line_bold("No write since last change (:%s! overrides)", cmd);
                 } else {
@@ -3319,11 +3313,12 @@ static void colon(char *buf)
                         editing = 0;
                 }
 # if ENABLE_FEATURE_VI_SET
-        } else if (strncmp(cmd, "set", i) == 0) {       // set or clear features
+        } else if (strncmp(cmd, "set", cmdlen) == 0     // set or clear features
+                IF_FEATURE_VI_SEARCH(&& cmdlen > 1)     // (do not confuse with "s /find/repl/")
+        ) {
 #  if ENABLE_FEATURE_VI_SETOPTS
                 char *argp, *argn, oldch;
 #  endif
-                // only blank is regarded as args delimiter. What about tab '\t'?
                 if (!args[0] || strcmp(args, "all") == 0) {
                         // print out values of all options
 #  if ENABLE_FEATURE_VI_SETOPTS
@@ -3370,7 +3365,7 @@ static void colon(char *buf)
 #  if ENABLE_FEATURE_VI_SETOPTS
                 argp = args;
                 while (*argp) {
-                        i = 0;
+                        int i = 0;
                         if (argp[0] == 'n' && argp[1] == 'o') // "noXXX"
                                 i = 2;
                         argn = skip_non_whitespace(argp);
@@ -3385,8 +3380,10 @@ static void colon(char *buf)
 
 # if ENABLE_FEATURE_VI_SEARCH
         } else if (cmd[0] == 's') {     // substitute a pattern with a replacement pattern
+                char c;
                 char *F, *R, *flags;
                 size_t len_F, len_R;
+                int i;
                 int gflag = 0;          // global replace flag
                 int subs = 0;   // number of substitutions
 #  if ENABLE_FEATURE_VI_VERBOSE_STATUS
@@ -3400,12 +3397,12 @@ static void colon(char *buf)
                 int undo = 0;
 #   endif
 #  endif
-
+                buf = skip_whitespace(buf + 1); // spaces allowed: "s  /find/repl/"
                 // F points to the "find" pattern
                 // R points to the "replace" pattern
                 // replace the cmd line delimiters "/" with NULs
-                c = buf[1];     // what is the delimiter
-                F = buf + 2;    // start of "find"
+                c = buf[0];     // what is the delimiter
+                F = buf + 1;    // start of "find"
                 R = strchr_backslash(F, c);     // middle delimiter
                 if (!R)
                         goto colon_s_fail;
@@ -3450,7 +3447,6 @@ static void colon(char *buf)
 #  else
                 len_R = strlen(R);
 #  endif
-
                 for (i = b; i <= e; i++) {      // so, :20,23 s \0 find \0 replace \0
                         char *ls = q;           // orig line start
                         char *found;
@@ -3522,15 +3518,16 @@ static void colon(char *buf)
                 regfree(&preg);
 #  endif
 # endif /* FEATURE_VI_SEARCH */
-        } else if (strncmp(cmd, "version", i) == 0) {  // show software version
+        } else if (strncmp(cmd, "version", cmdlen) == 0) {  // show software version
                 status_line(BB_VER);
-        } else if (strncmp(cmd, "write", i) == 0  // write text to file
+        } else if (strncmp(cmd, "write", cmdlen) == 0  // write text to file
                 || strcmp(cmd, "wq") == 0
                 || strcmp(cmd, "wn") == 0
                 || (cmd[0] == 'x' && !cmd[1])
         ) {
-                int size;
+                int size, l;
                 //int forced = FALSE;
+                char *fn = current_filename;
 
                 // is there a file name to write to?
                 if (args[0]) {
@@ -3539,8 +3536,10 @@ static void colon(char *buf)
                         exp = expand_args(args);
                         if (exp == NULL)
                                 goto ret;
-                        if (!useforce && (fn == NULL || strcmp(fn, exp) != 0) &&
-                                        stat(exp, &statbuf) == 0) {
+                        if (!useforce
+                         && (fn == NULL || strcmp(fn, exp) != 0)
+                         && stat(exp, &statbuf) == 0
+                        ) {
                                 status_line_bold("File exists (:w! overrides)");
                                 goto ret;
                         }
@@ -3559,12 +3558,10 @@ static void colon(char *buf)
                         // system(syscmd);
                         // forced = TRUE;
                 //}
+                size = l = 0;
                 if (modified_count != 0 || cmd[0] != 'x') {
                         size = r - q + 1;
                         l = file_write(fn, q, r);
-                } else {
-                        size = 0;
-                        l = 0;
                 }
                 //if (useforce && forced) {
                         // chmod u-w
@@ -3577,8 +3574,8 @@ static void colon(char *buf)
                                 status_line_bold_errno(fn);
                 } else {
                         // how many lines written
-                        li = count_lines(q, q + l - 1);
-                        status_line("'%s' %uL, %uC", fn, li, l);
+                        int lines = count_lines(q, q + l - 1);
+                        status_line("'%s' %uL, %uC", fn, lines, l);
                         if (l == size) {
                                 if (q == text && q + l == end) {
                                         modified_count = 0;
@@ -3590,37 +3587,35 @@ static void colon(char *buf)
                                         // are there other files to edit?
                                         int n = cmdline_filecnt - optind - 1;
                                         if (n > 0) {
-                                                if (useforce) {
-                                                        // force end of argv list
-                                                        optind = cmdline_filecnt;
-                                                } else {
+                                                if (!useforce) {
                                                         status_line_bold("%u more file(s) to edit", n);
                                                         goto ret;
                                                 }
+                                                // force end of argv list
+                                                optind = cmdline_filecnt;
                                         }
                                         editing = 0;
                                 }
                         }
                 }
 # if ENABLE_FEATURE_VI_YANKMARK
-        } else if (strncmp(cmd, "yank", i) == 0) {      // yank lines
+        } else if (strncmp(cmd, "yank", cmdlen) == 0) { // yank lines
+                int lines;
                 if (!GOT_ADDRESS) {     // no addr given- use defaults
                         q = begin_line(dot);    // assume .,. for the range
                         r = end_line(dot);
                 }
                 text_yank(q, r, YDreg, WHOLE);
-                li = count_lines(q, r);
+                lines = count_lines(q, r);
                 status_line("Yank %d lines (%d chars) into [%c]",
-                                li, strlen(reg[YDreg]), what_reg());
+                                lines, strlen(reg[YDreg]), what_reg());
 # endif
         } else {
                 // cmd unknown
                 not_implemented(cmd);
         }
  ret:
-# if ENABLE_FEATURE_VI_COLON_EXPAND
-        free(exp);
-# endif
+        IF_FEATURE_VI_COLON_EXPAND(free(exp);)
         dot = bound_dot(dot);   // make sure "dot" is valid
         return;
 # if ENABLE_FEATURE_VI_SEARCH
@@ -4977,8 +4972,7 @@ static void run_cmds(char *p)
                 if (p)
                         while (*p == '\n')
                                 *p++ = '\0';
-                if (strlen(q) < MAX_INPUT_LEN)
-                        colon(q);
+                colon(q);
         }
 }
 #endif
diff --git a/include/libbb.h b/include/libbb.h
index 6c4fe17c9..6ce99abda 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -457,7 +457,12 @@ unsigned FAST_FUNC bb_popcnt_long(unsigned long m);
 #define bb_popcnt_long(m) bb_popcnt_32(m)
 #endif
 
-unsigned long FAST_FUNC isqrt(unsigned long long N);
+unsigned FAST_FUNC isqrt(unsigned long N);
+#if LLONG_MAX > LONG_MAX
+unsigned long FAST_FUNC isqrt_ull(unsigned long long N);
+#else
+# define isqrt_ull(N) isqrt(N)
+#endif
 
 unsigned long long monotonic_ns(void) FAST_FUNC;
 unsigned long long monotonic_us(void) FAST_FUNC;
@@ -1042,6 +1047,8 @@ int parse_pasv_epsv(char *buf) FAST_FUNC;
 /* 0 if argv[0] is NULL: */
 unsigned string_array_len(char **argv) FAST_FUNC;
 void overlapping_strcpy(char *dst, const char *src) FAST_FUNC;
+/* Like strncpy but make sure the resulting string is always 0 terminated: */
+/* writes SIZE chars, the [SIZE-1] char is always NUL (unless SIZE==0). */
 char *safe_strncpy(char *dst, const char *src, size_t size) FAST_FUNC;
 char *strncpy_IFNAMSIZ(char *dst, const char *src) FAST_FUNC;
 unsigned count_strstr(const char *str, const char *sub) FAST_FUNC;
@@ -1053,6 +1060,8 @@ int bb_putchar(int ch) FAST_FUNC;
 int bb_putchar_stderr(char ch) FAST_FUNC;
 int fputs_stdout(const char *s) FAST_FUNC;
 char *xasprintf(const char *format, ...) __attribute__ ((format(printf, 1, 2))) RETURNS_MALLOC;
+char *xasprintf_and_free(char *allocated, const char *format, ...) __attribute__ ((format(printf, 2, 3))) RETURNS_MALLOC;
+#define xasprintf_inplace(allocated, ...) ((allocated) = xasprintf_and_free((allocated), __VA_ARGS__))
 char *auto_string(char *str) FAST_FUNC;
 // gcc-4.1.1 still isn't good enough at optimizing it
 // (+200 bytes compared to macro)
diff --git a/klibc-utils/resume.c b/klibc-utils/resume.c
index 7b9d18b5d..179413627 100644
--- a/klibc-utils/resume.c
+++ b/klibc-utils/resume.c
@@ -39,7 +39,7 @@ static dev_t name_to_dev_t(const char *devname)
         struct stat st;
         int r;
 
-        if (strncmp(devname, "/dev/", 5) != 0) {
+        if (!is_prefixed_with(devname, "/dev/")) {
                 char *cptr;
 
                 cptr = strchr(devname, ':');
@@ -59,7 +59,7 @@ static dev_t name_to_dev_t(const char *devname)
                                 return res;
                 }
 
-                devname = xasprintf("/dev/%s", devname);
+                devname = concat_path_file("/dev", devname);
         }
         /* Now devname is always "/dev/FOO" */
 
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index b2dcf93e0..481cc278e 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -1413,8 +1413,11 @@ int main(int argc UNUSED_PARAM, char **argv)
 # endif
         lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
 # if !ENABLE_BUSYBOX
-        if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
+        if (argv[1] && argv[1][0] != '-' /* do not match "busybox --OPT" */
+         && is_prefixed_with(bb_basename(argv[0]), "busybox")
+        ) {
                 argv++;
+        }
 # endif
         applet_name = argv[0];
         if (applet_name[0] == '-')
diff --git a/libbb/isqrt.c b/libbb/isqrt.c
index 817b7d036..507c7d637 100644
--- a/libbb/isqrt.c
+++ b/libbb/isqrt.c
@@ -9,15 +9,42 @@
 #ifndef ISQRT_TEST
 # include "libbb.h"
 #else
-/* gcc -DISQRT_TEST -Wall -O2 isqrt.c -oisqrt && ./isqrt $((RANDOM*RANDOM)) */
+// gcc -DISQRT_TEST -Wall -Os -ffunction-sections isqrt.c -S -fverbose-asm
+// gcc -DISQRT_TEST -Wall -Os -ffunction-sections isqrt.c -c
+// gcc -DISQRT_TEST -Wall -Os -ffunction-sections isqrt.c -oisqrt && ./isqrt $((RANDOM*RANDOM))
 # include <stdlib.h>
 # include <stdio.h>
 # include <time.h>
+# include <limits.h>
 # define FAST_FUNC /* nothing */
 #endif
 
 /* Returns such x that x+1 > sqrt(N) */
-unsigned long FAST_FUNC isqrt(unsigned long long N)
+
+/* Stolen from kernel code */
+unsigned FAST_FUNC isqrt(unsigned long x)
+{
+        unsigned long y = 0;
+        unsigned long m = 1UL << (8*sizeof(x) - 2);
+        // ^^^^^ should be m = 1UL << ((fls(x) - 1) & ~1UL);
+        // but calculating fls() would take time and code
+
+        do {
+                unsigned long b = y + m;
+                y >>= 1;
+                if (x >= b) {
+                        x -= b;
+                        y += m;
+                }
+                m >>= 2;
+        } while (m);
+        return y;
+}
+
+#if LLONG_MAX > LONG_MAX
+# if defined(i386)
+/* Smaller code on this register-starved arch */
+unsigned long FAST_FUNC isqrt_ull(unsigned long long N)
 {
         unsigned long x;
         unsigned shift;
@@ -33,15 +60,40 @@ unsigned long FAST_FUNC isqrt(unsigned long long N)
         } while ((int)shift >= 0);
         return x;
 }
+# else
+/* Stolen from kernel code */
+unsigned long FAST_FUNC isqrt_ull(unsigned long long x)
+{
+        unsigned long long y = 0;
+        unsigned long long m = 1ULL << (8*sizeof(x) - 2);
+        // ^^^^^ should be m = 1ULL << ((fls(x) - 1) & ~1ULL);
+        // but calculating fls() would take time and code
+
+        do {
+                unsigned long long b = y + m;
+                y >>= 1;
+                if (x >= b) {
+                        x -= b;
+                        y += m;
+                }
+                m >>= 2;
+        } while (m);
+        return y;
+}
+# endif
+#endif /* wide version needed */
 
 #ifdef ISQRT_TEST
+# if LLONG_MAX == LONG_MAX
+#  define isqrt_ull(N) isqrt(N)
+# endif
 int main(int argc, char **argv)
 {
         unsigned long long n = argv[1] ? strtoull(argv[1], NULL, 0) : time(NULL);
         for (;;) {
                 unsigned long h;
                 n--;
-                h = isqrt(n);
+                h = isqrt_ull(n);
                 if (!(n & 0xffff))
                         printf("isqrt(%llx)=%lx\n", n, h);
                 if ((unsigned long long)h * h > n) {
diff --git a/libbb/xfuncs_printf.c b/libbb/xfuncs_printf.c
index 675c91d68..f4d1b913a 100644
--- a/libbb/xfuncs_printf.c
+++ b/libbb/xfuncs_printf.c
@@ -351,6 +351,22 @@ char* xasprintf(const char *format, ...)
         return string_ptr;
 }
 
+char* xasprintf_and_free(char *allocated, const char *format, ...)
+{
+        va_list p;
+        int r;
+        char *string_ptr;
+
+        va_start(p, format);
+        r = vasprintf(&string_ptr, format, p);
+        va_end(p);
+
+        if (r < 0)
+                bb_die_memory_exhausted();
+        free(allocated);
+        return string_ptr;
+}
+
 void FAST_FUNC xsetenv(const char *key, const char *value)
 {
         if (setenv(key, value, 1))
diff --git a/loginutils/add-remove-shell.c b/loginutils/add-remove-shell.c
index 2470050e7..ff54ab5db 100644
--- a/loginutils/add-remove-shell.c
+++ b/loginutils/add-remove-shell.c
@@ -64,7 +64,6 @@ int add_remove_shell_main(int argc UNUSED_PARAM, char **argv)
         if (orig_fp)
                 xfstat(fileno(orig_fp), &sb, orig_fn);
 
-
         new_fn = xasprintf("%s.tmp", orig_fn);
         /*
          * O_TRUNC or O_EXCL? At the first glance, O_EXCL looks better,
diff --git a/loginutils/adduser.c b/loginutils/adduser.c
index bfab05203..ac43feb48 100644
--- a/loginutils/adduser.c
+++ b/loginutils/adduser.c
@@ -227,7 +227,7 @@ int adduser_main(int argc UNUSED_PARAM, char **argv)
         die_if_bad_username(pw.pw_name);
         if (!pw.pw_dir) {
                 /* create string for $HOME if not specified already */
-                pw.pw_dir = xasprintf("/home/%s", argv[0]);
+                pw.pw_dir = concat_path_file("/home", argv[0]);
         }
         pw.pw_passwd = (char *)"x";
         if (opts & OPT_SYSTEM_ACCOUNT) {
diff --git a/loginutils/getty.c b/loginutils/getty.c
index 4581cc9f7..67a08f487 100644
--- a/loginutils/getty.c
+++ b/loginutils/getty.c
@@ -213,7 +213,7 @@ static void open_tty(void)
         /* Set up new standard input, unless we are given an already opened port */
         if (NOT_LONE_DASH(G.tty_name)) {
                 if (G.tty_name[0] != '/')
-                        G.tty_name = xasprintf("/dev/%s", G.tty_name); /* will leak it */
+                        G.tty_name = concat_path_file("/dev", G.tty_name); /* will leak it */
 
                 /* Open the tty as standard input */
                 debug("open(2)\n");
diff --git a/miscutils/devfsd.c b/miscutils/devfsd.c
index 642cd3637..d57691414 100644
--- a/miscutils/devfsd.c
+++ b/miscutils/devfsd.c
@@ -962,7 +962,6 @@ static void action_compat(const struct devfsd_notify_struct *info, unsigned int
                         dest_name = dest_buf;
                         compat_name = compat_buf;
 
-
                         /* 1 == scsi/generic  2 == scsi/disc 3 == scsi/cd 6 == ide/host/disc 7 == ide/host/cd */
                         if (i == 1 || i == 2 || i == 3 || i == 6 || i ==7)
                                 sprintf(compat_buf, fmt[i], host, bus, target, lun);
diff --git a/miscutils/less.c b/miscutils/less.c
index 5a8fc5a74..91403a252 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -857,13 +857,13 @@ static void print_found(const char *line)
         goto start;
 
         while (match_status == 0) {
-                char *new = xasprintf("%s%.*s"HIGHLIGHT"%.*s"NORMAL,
-                                growline ? growline : "",
-                                (int)match_structs.rm_so, str,
-                                (int)(match_structs.rm_eo - match_structs.rm_so),
-                                                str + match_structs.rm_so);
-                free(growline);
-                growline = new;
+                xasprintf_inplace(growline,
+                        "%s%.*s"HIGHLIGHT"%.*s"NORMAL,
+                        growline ? growline : "",
+                        (int)match_structs.rm_so,
+                                str,
+                        (int)(match_structs.rm_eo - match_structs.rm_so),
+                                str + match_structs.rm_so);
                 str += match_structs.rm_eo;
                 line += match_structs.rm_eo;
                 eflags = REG_NOTBOL;
diff --git a/miscutils/man.c b/miscutils/man.c
index 38c1b9aa3..cf67f1538 100644
--- a/miscutils/man.c
+++ b/miscutils/man.c
@@ -73,7 +73,7 @@ struct globals {
 
 static int show_manpage(char *man_filename, int man, int level);
 
-static int run_pipe(char *man_filename, int man, int level)
+static int run_man_pipe(char *man_filename, int man, int level)
 {
         char *cmd;
 
@@ -115,24 +115,36 @@ static int run_pipe(char *man_filename, int man, int level)
                  * ".so man7/path_resolution.7\n<junk>"
                  */
                 *strchrnul(line, '\n') = '\0';
-                linkname = skip_whitespace(&line[4]);
-
-                /* If link has no slashes, we just replace man page name.
-                 * If link has slashes (however many), we go back *once*.
-                 * ".so zzz/ggg/page.3" does NOT go back two levels. */
+                linkname = skip_whitespace(line + 4);
+//testcase:
+// cd /usr/share/man/man2
+// man ./path_resolution.2.gz
+                while (man_filename[0] == '.' && man_filename[1] == '/')
+                        man_filename += 2;
                 p = strrchr(man_filename, '/');
                 if (!p)
-                        goto ordinary_manpage;
-                *p = '\0';
+                        man_filename = (char*)".." + 1; /* "NAME.N" -> "." */
+                else
+                        *p = '\0'; /* "PFX/manN/NAME.N" -> "PFX/manN" */
+
+                /* If link has slashes (however many), we go back *once*.
+                 * ".so zzz/ggg/page.3" does NOT go back two levels.
+                 */
                 if (strchr(linkname, '/')) {
+                        if (!p) { /* man_filename had no path */
+                                man_filename--; /* ".." */
+                                goto append_link;
+                        }
                         p = strrchr(man_filename, '/');
                         if (!p)
-                                goto ordinary_manpage;
-                        *p = '\0';
-                }
+                                man_filename = (char*)".." + 1; /* "manN" -> "." */
+                        else
+                                *p = '\0'; /* "PFX/manN" -> "PFX" */
+                } /* else (link has no slashes): will do "PFX/manN" -> "PFX/manN/link" */
 
                 /* Links do not have .gz extensions, even if manpage
                  * is compressed */
+ append_link:
                 man_filename = xasprintf("%s/%s", man_filename, linkname);
                 free(line);
                 /* Note: we leak "new" man_filename string as well... */
@@ -172,26 +184,26 @@ static int show_manpage(char *man_filename, int man, int level)
 #endif
 
 #if ENABLE_FEATURE_SEAMLESS_LZMA
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 #if ENABLE_FEATURE_SEAMLESS_XZ
         strcpy(ext, "xz");
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 #if ENABLE_FEATURE_SEAMLESS_BZ2
         strcpy(ext, "bz2");
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 #if ENABLE_FEATURE_SEAMLESS_GZ
         strcpy(ext, "gz");
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 
-        return run_pipe(man_filename, man, level);
+        return run_man_pipe(man_filename, man, level);
 }
 
 static char **add_MANPATH(char **man_path_list, int *count_mp, char *path)
diff --git a/modutils/modprobe-small.c b/modutils/modprobe-small.c
index 31a215a29..7f584102d 100644
--- a/modutils/modprobe-small.c
+++ b/modutils/modprobe-small.c
@@ -723,7 +723,7 @@ static int process_module(char *name, const char *cmdline_options)
 
         options = NULL;
         if (!is_remove) {
-                char *opt_filename = xasprintf("/etc/modules/%s", name);
+                char *opt_filename = concat_path_file("/etc/modules", name);
                 options = xmalloc_open_read_close(opt_filename, NULL);
                 if (options)
                         replace_char(options, '\n', ' ');
@@ -731,10 +731,8 @@ static int process_module(char *name, const char *cmdline_options)
                 if (cmdline_options) {
                         /* NB: cmdline_options always have one leading ' '
                          * (see main()), we remove it here */
-                        char *op = xasprintf(options ? "%s %s" : "%s %s" + 3,
+                        xasprintf_inplace(options, options ? "%s %s" : "%s %s" + 3,
                                                 cmdline_options + 1, options);
-                        free(options);
-                        options = op;
                 }
 #endif
                 free(opt_filename);
@@ -1010,9 +1008,7 @@ int modprobe_main(int argc UNUSED_PARAM, char **argv)
                 char **arg = argv;
                 while (*++arg) {
                         /* Enclose options in quotes */
-                        char *s = options;
-                        options = xasprintf("%s \"%s\"", s ? s : "", *arg);
-                        free(s);
+                        xasprintf_inplace(options, "%s \"%s\"", options ? options : "", *arg);
                         *arg = NULL;
                 }
 # else
diff --git a/networking/ftpd.c b/networking/ftpd.c
index c3125410e..96db5d9fd 100644
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -491,19 +491,18 @@ static void
 handle_pasv(void)
 {
         unsigned port;
-        char *addr, *response;
+        char *response;
 
         port = bind_for_passive_mode();
 
         if (G.local_addr->u.sa.sa_family == AF_INET)
-                addr = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa);
+                response = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa);
         else /* seen this in the wild done by other ftp servers: */
-                addr = xstrdup("0.0.0.0");
-        replace_char(addr, '.', ',');
+                response = xstrdup("0.0.0.0");
+        replace_char(response, '.', ',');
 
-        response = xasprintf(STR(FTP_PASVOK)" PASV ok (%s,%u,%u)\r\n",
-                        addr, (int)(port >> 8), (int)(port & 255));
-        free(addr);
+        xasprintf_inplace(response, STR(FTP_PASVOK)" PASV ok (%s,%u,%u)\r\n",
+                        response, (int)(port >> 8), (int)(port & 255));
         cmdio_write_raw(response);
         free(response);
 }
diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index 9c3640be7..bc2dca506 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -895,16 +895,15 @@ static struct interfaces_file_t *read_interfaces(const char *filename, struct in
         while ((buf = xmalloc_fgetline(f)) != NULL) {
 #if ENABLE_DESKTOP
                 /* Trailing "\" concatenates lines */
+//TODO: check how to handle "line\\" (double backslashes)
                 char *p;
                 while ((p = last_char_is(buf, '\\')) != NULL) {
                         *p = '\0';
                         rest_of_line = xmalloc_fgetline(f);
                         if (!rest_of_line)
                                 break;
-                        p = xasprintf("%s%s", buf, rest_of_line);
-                        free(buf);
+                        xasprintf_inplace(buf, "%s%s", buf, rest_of_line);
                         free(rest_of_line);
-                        buf = p;
                 }
 #endif
                 rest_of_line = buf;
diff --git a/networking/netstat.c b/networking/netstat.c
index 807800a62..d7afa8fdd 100644
--- a/networking/netstat.c
+++ b/networking/netstat.c
@@ -391,7 +391,7 @@ static const char *get_sname(int port, const char *proto, int numeric)
 
 static char *ip_port_str(struct sockaddr *addr, int port, const char *proto, int numeric)
 {
-        char *host, *host_port;
+        char *host;
 
         /* Code which used "*" for INADDR_ANY is removed: it's ambiguous
          * in IPv6, while "0.0.0.0" is not. */
@@ -402,9 +402,8 @@ static char *ip_port_str(struct sockaddr *addr, int port, const char *proto, int
         if (!host)
                 host = xmalloc_sockaddr2dotted_noport(addr);
 
-        host_port = xasprintf("%s:%s", host, get_sname(htons(port), proto, numeric));
-        free(host);
-        return host_port;
+        xasprintf_inplace(host, "%s:%s", host, get_sname(htons(port), proto, numeric));
+        return host;
 }
 
 struct inet_params {
diff --git a/networking/ntpd.c b/networking/ntpd.c
index efe9f5326..595000b11 100644
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -2395,7 +2395,7 @@ static NOINLINE void ntp_init(char **argv)
                 while (peers) {
                         char *peer = llist_pop(&peers);
                         key_entry_t *key_entry = NULL;
-                        if (strncmp(peer, "keyno:", 6) == 0) {
+                        if (is_prefixed_with(peer, "keyno:")) {
                                 char *end;
                                 int key_id;
                                 peer += 6;
diff --git a/networking/tls.h b/networking/tls.h
index eee5a7617..fde2e4d3d 100644
--- a/networking/tls.h
+++ b/networking/tls.h
@@ -10,7 +10,6 @@
  */
 #include "libbb.h"
 
-
 #if !ENABLE_FEATURE_TLS_SCHANNEL
 /* Config tweaks */
 #define HAVE_NATIVE_INT64
@@ -32,16 +31,18 @@
 # define PSTM_32BIT
 # define PSTM_X86
 #endif
-//#if defined(__GNUC__) && defined(__x86_64__)
-//  /* PSTM_X86_64 works correctly, but +782 bytes. */
-//  /* Looks like most of the growth is because of PSTM_64BIT. */
+#if defined(__GNUC__) && defined(__x86_64__)
+  /* PSTM_64BIT + PSTM_X86_64 works correctly, but:
+   * +928 bytes if PSTM_64BIT but !PSTM_X86_64
+   * +1003 bytes with INNERMUL8 (loop unrolling in pstm_montgomery_reduce())
+   * +664 bytes without INNERMUL8
+   */
 //# define PSTM_64BIT
 //# define PSTM_X86_64
-//#endif
+#endif
 //#if SOME_COND #define PSTM_MIPS, #define PSTM_32BIT
 //#if SOME_COND #define PSTM_ARM,  #define PSTM_32BIT
 
-
 #define PS_SUCCESS              0
 #define PS_FAILURE              -1
 #define PS_ARG_FAIL             -6      /* Failure due to bad function param */
@@ -52,14 +53,14 @@
 #define PS_TRUE         1
 #define PS_FALSE        0
 
+#undef ENDIAN_BIG
+#undef ENDIAN_LITTLE
 #if BB_BIG_ENDIAN
 # define ENDIAN_BIG     1
-# undef  ENDIAN_LITTLE
 //#????  ENDIAN_32BITWORD
 // controls only STORE32L, which we don't use
 #else
 # define ENDIAN_LITTLE  1
-# undef  ENDIAN_BIG
 #endif
 
 typedef uint64_t uint64;
@@ -99,7 +100,6 @@ void tls_get_random(void *buf, unsigned len) FAST_FUNC;
 #undef  min
 #define min(x, y) ((x) < (y) ? (x) : (y))
 
-
 #include "tls_pstm.h"
 #include "tls_aes.h"
 #include "tls_aesgcm.h"
diff --git a/networking/tls_pstm_montgomery_reduce.c b/networking/tls_pstm_montgomery_reduce.c
index 4181a0590..e63e590db 100644
--- a/networking/tls_pstm_montgomery_reduce.c
+++ b/networking/tls_pstm_montgomery_reduce.c
@@ -135,7 +135,7 @@ asm(                                                       \
         :"0"(_c[LO]), "1"(cy), "r"(mu), "r"(*tmpm++)           \
         : "%rax", "%rdx", "cc")
 
-#define INNERMUL8                               \
+#define INNERMUL8_disabled_for_bbox                             \
 asm(                                                    \
         "movq 0(%5),%%rax    \n\t"  \
         "movq 0(%2),%%r10    \n\t"  \
@@ -398,7 +398,7 @@ int32 FAST_FUNC pstm_montgomery_reduce(psPool_t *pool, pstm_int *a, pstm_int *m,
                 _c   = c + x;
                 tmpm = m->dp;
                 y = 0;
-#ifdef PSTM_X86_64
+#ifdef INNERMUL8 //bbox: PSTM_X86_64
                 for (; y < (pa & ~7); y += 8) {
                         INNERMUL8;
                         _c   += 8;
diff --git a/procps/watch.c b/procps/watch.c
index d7c3ad55e..51b324b44 100644
--- a/procps/watch.c
+++ b/procps/watch.c
@@ -19,11 +19,12 @@
 //kbuild:lib-$(CONFIG_WATCH) += watch.o
 
 //usage:#define watch_trivial_usage
-//usage:       "[-n SEC] [-t] PROG ARGS"
+//usage:       "[-n SEC] [-tx] PROG ARGS"
 //usage:#define watch_full_usage "\n\n"
 //usage:       "Run PROG periodically\n"
 //usage:     "\n        -n SEC  Period (default 2)"
 //usage:     "\n        -t      Don't print header"
+//usage:     "\n        -x      exec(PROG,ARGS) instead of sh -c 'PROG ARGS'"
 //usage:
 //usage:#define watch_example_usage
 //usage:       "$ watch date\n"
@@ -56,6 +57,7 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
         unsigned opt;
         unsigned width, new_width;
         char *header;
+        char **argv0;
         char *cmd;
 
 #if 0 // maybe ENABLE_DESKTOP?
@@ -66,27 +68,32 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
 
         // "+": stop at first non-option (procps 3.x only); -n NUM
         // at least one param
-        opt = getopt32(argv, "^+" "dtn:" "\0" "-1", &period_str);
+        opt = getopt32(argv, "^+" "dtn:x" "\0" "-1", &period_str);
         argv += optind;
 
-        // watch from both procps 2.x and 3.x does concatenation. Example:
-        // watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param
+        // watch from both procps 2.x and 3.x concatenates (unless -x).
+        // Example:
+        // watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param.
+        argv0 = argv;
+        // If -x, cmd is only used for printing header
 #if ENABLE_PLATFORM_MINGW32
         cmd = NULL;
         do {
                 cmd = xappendword(cmd, *argv);
         } while (*++argv);
 #else
-        cmd = *argv;
+        cmd = xstrdup(*argv);
         while (*++argv)
-                cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd
+                xasprintf_inplace(cmd, "%s %s", cmd, *argv);
 #endif
+        if (opt & (1 << 3))
+                argv = argv0; // If -x, restore argv[0] to !NULL
 
         period = parse_duration_str(period_str);
         width = (unsigned)-1; // make sure first time new_width != width
         header = NULL;
         while (1) {
-                /* home; clear to the end of screen */
+                // home; clear to the end of screen
                 printf(ESC"[H" ESC"[J");
                 if (!(opt & 0x2)) { // no -t
                         const unsigned time_len = sizeof("1234-67-90 23:56:89");
@@ -119,7 +126,10 @@ int watch_main(int argc UNUSED_PARAM, char **argv)
                 // TODO: 'real' watch pipes cmd's output to itself
                 // and does not allow it to overflow the screen
                 // (taking into account linewrap!)
-                system(cmd);
+                if (argv[0]) // -x?
+                        spawn_and_wait(argv); // yes
+                else
+                        system(cmd);
                 sleep_for_duration(period);
         }
         return 0; // gcc thinks we can reach this :)
diff --git a/shell/ash.c b/shell/ash.c
index 43f92bfae..bb8ac53d6 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -1384,7 +1384,7 @@ static void dbg_show_dirtymem(const char *msg)
         p = buf;
         for (;;) {
                 char *e = strchrnul(p, '\n');
-                if (strncmp(p, "Private_Dirty:", 14) == 0) {
+                if (is_prefixed_with(p, "Private_Dirty:")) {
                         p = skip_whitespace(p + 14);
                         bb_error_msg("%s:%.*s", msg, (int)(e - p), p);
                         break;
diff --git a/shell/hush.c b/shell/hush.c
index da0db7948..23e7f512f 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2941,12 +2941,9 @@ static void i_prepend_to_alias_buffer(struct in_str *i, char *prepend, char ch)
                  * a
                  * ^^^ runs "echo A: c"
                  */
-                char *old = i->albuf;
                 //bb_error_msg("before'%s' p'%s'", i->albuf, i->p);
-                i->albuf = xasprintf("%s%c%s", prepend, ch, i->p);
-                i->p = i->albuf;
+                i->p = xasprintf_inplace(i->albuf, "%s%c%s", prepend, ch, i->p);
                 //bb_error_msg("after'%s' p'%s'", i->albuf, i->p);
-                free(old);
                 return;
         }
         i->saved_ibuf = i->p;
diff --git a/util-linux/acpid.c b/util-linux/acpid.c
index 5c0bb1768..386b988d2 100644
--- a/util-linux/acpid.c
+++ b/util-linux/acpid.c
@@ -145,7 +145,7 @@ struct globals {
 static void process_event(const char *event)
 {
         struct stat st;
-        char *handler = xasprintf("./%s", event);
+        char *handler = concat_path_file(".", event);
         const char *args[] = { "run-parts", handler, NULL };
 
         // log the event
diff --git a/util-linux/dmesg.c b/util-linux/dmesg.c
index 5d8f01a64..39eecc345 100644
--- a/util-linux/dmesg.c
+++ b/util-linux/dmesg.c
@@ -91,7 +91,6 @@ int dmesg_main(int argc UNUSED_PARAM, char **argv)
         if (len == 0)
                 return EXIT_SUCCESS;
 
-
         if (ENABLE_FEATURE_DMESG_PRETTY && !(opts & OPT_r)) {
                 int last = '\n';
                 int in = 0;
diff --git a/util-linux/lsblk.c b/util-linux/lsblk.c
index a482bfbbc..3bd40bcb4 100644
--- a/util-linux/lsblk.c
+++ b/util-linux/lsblk.c
@@ -101,10 +101,10 @@ static char *get_mountpoints(const char *majmin)
 
         mountpoints = NULL;
         len = strlen(majmin);
-        p = G.mountinfo; // "/proc/self/mountinfo"
+        p = G.mountinfo; // contents of "/proc/self/mountinfo"
         /* lines a-la "63 1 259:3 / /MNTPOINT per-mount_options - ext4 /dev/NAME per-superblock_options" */
         while (*p) {
-                char *e, *f;
+                char *e;
 
                 p = skip_non_whitespace(p);
                 if (*p != ' ') break;
@@ -127,12 +127,11 @@ static char *get_mountpoints(const char *majmin)
                 // at " /MNTPOINT"
                 e = skip_non_whitespace(p + 1);
                 // e is at the end of " /MNTPOINT"
-                f = mountpoints;
 // NO. We return " /MNT1 /MNT2 /MNT3" _with_ leading space!
-//              if (!f)
+//              if (!mountpoints)
 //                      p++;
-                mountpoints = xasprintf("%s%.*s", f ? f : "", (int)(e - p), p);
-                free(f);
+                xasprintf_inplace(mountpoints, "%s%.*s",
+                        mountpoints ? mountpoints : "", (int)(e - p), p);
         }
         return mountpoints;
 }
diff --git a/util-linux/lspci.c b/util-linux/lspci.c
index 25be23a01..1a43f71e2 100644
--- a/util-linux/lspci.c
+++ b/util-linux/lspci.c
@@ -81,7 +81,6 @@ static int FAST_FUNC fileAction(struct recursive_state *state UNUSED_PARAM,
         }
         config_close(parser);
 
-
         if (option_mask32 & OPT_m) {
                 printf("%s \"Class %04x\" \"%04x\" \"%04x\" \"%04x\" \"%04x\"",
                         pci_slot_name, pci_class, pci_vid, pci_did,
diff --git a/util-linux/mount.c b/util-linux/mount.c
index d0f0ae1ad..d0d109c09 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -556,27 +556,33 @@ static int verbose_mount(const char *source, const char *target,
 #endif
 
 // Append mount options to string
+// ("merge two comma-separated lists" is a good candidate for libbb!)
 static void append_mount_options(char **oldopts, const char *newopts)
 {
         if (*oldopts && **oldopts) {
+//TODO: do this unconditionally?
+//this way, newopts of "opt1,opt2,opt1"
+//will be de-duped into "opt1,opt2" in _both_ cases
+//(whether or now old opts are empty)
+//the only modification needed is to not prepend extra comma
+//when old opts is "".
                 // Do not insert options which are already there
-                while (newopts[0]) {
+                while (*newopts) {
                         char *p;
                         int len;
 
+                        //if (*newopts == ',') { newopts++; continue; }
                         len = strchrnul(newopts, ',') - newopts;
                         p = *oldopts;
                         while (1) {
-                                if (!strncmp(p, newopts, len)
+                                if (strncmp(p, newopts, len) == 0
                                  && (p[len] == ',' || p[len] == '\0'))
                                         goto skip;
-                                p = strchr(p,',');
+                                p = strchr(p, ',');
                                 if (!p) break;
                                 p++;
                         }
-                        p = xasprintf("%s,%.*s", *oldopts, len, newopts);
-                        free(*oldopts);
-                        *oldopts = p;
+                        xasprintf_inplace(*oldopts, "%s,%.*s", *oldopts, len, newopts);
  skip:
                         newopts += len;
                         while (*newopts == ',') newopts++;
@@ -2065,12 +2071,11 @@ static int singlemount(struct mntent *mp, int ignore_busy)
                 if (!is_prefixed_with(filteropts, ",ip="+1)
                  && !strstr(filteropts, ",ip=")
                 ) {
-                        char *dotted, *ip;
+                        char *ip;
                         // Insert "ip=..." option into options
-                        dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
+                        ip = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
                         if (ENABLE_FEATURE_CLEAN_UP) free(lsa);
-                        ip = xasprintf("ip=%s", dotted);
-                        if (ENABLE_FEATURE_CLEAN_UP) free(dotted);
+                        xasprintf_inplace(ip, "ip=%s", ip);
 // Note: IPv6 scoped addresses ("host%iface", see RFC 4007) should be
 // handled by libc in getnameinfo() (inside xmalloc_sockaddr2dotted_noport()).
 // Currently, glibc does not support that (has no NI_NUMERICSCOPE),
diff --git a/util-linux/volume_id/get_devname.c b/util-linux/volume_id/get_devname.c
index 39155f256..52bb8e03a 100644
--- a/util-linux/volume_id/get_devname.c
+++ b/util-linux/volume_id/get_devname.c
@@ -110,7 +110,7 @@ uuidcache_check_device(struct recursive_state *state UNUSED_PARAM,
         /* note: this check rejects links to devices, among other nodes */
         if (!S_ISBLK(statbuf->st_mode)
 #if ENABLE_FEATURE_VOLUMEID_UBIFS
-         && !(S_ISCHR(statbuf->st_mode) && strncmp(bb_basename(device), "ubi", 3) == 0)
+         && !(S_ISCHR(statbuf->st_mode) && is_prefixed_with(bb_basename(device), "ubi"))
 #endif
         )
                 return TRUE;
diff --git a/util-linux/volume_id/unused_lvm.c b/util-linux/volume_id/unused_lvm.c
index 649306c85..512aa7962 100644
--- a/util-linux/volume_id/unused_lvm.c
+++ b/util-linux/volume_id/unused_lvm.c
@@ -74,7 +74,6 @@ int FAST_FUNC volume_id_probe_lvm2(struct volume_id *id, uint64_t off)
         if (buf == NULL)
                 return -1;
 
-
         for (soff = 0; soff < LVM2LABEL_SCAN_SECTORS * 0x200; soff += 0x200) {
                 lvm = (struct lvm2_super_block *) &buf[soff];