Merge branch 'busybox' into merge

3 files changed, 67 insertions, 46 deletions

diff --git a/editors/diff.c b/editors/diff.c
index f2eeb8257..975bc4603 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -295,17 +295,6 @@ static int search(const int *c, int k, int y, const struct cand *list)
         }
 }
 
-static unsigned isqrt(unsigned n)
-{
-        unsigned x = 1;
-        while (1) {
-                const unsigned y = x;
-                x = ((n / x) + x) >> 1;
-                if (x <= (y + 1) && x >= (y - 1))
-                        return x;
-        }
-}
-
 static void stone(const int *a, int n, const int *b, int *J, int pref)
 {
         const unsigned isq = isqrt(n);
@@ -730,9 +719,19 @@ static int diffreg(char *file[2])
         fp[0] = stdin;
         fp[1] = stdin;
         for (i = 0; i < 2; i++) {
-                int fd = open_or_warn_stdin(file[i]);
-                if (fd == -1)
-                        goto out;
+                int fd = STDIN_FILENO;
+                if (!LONE_DASH(file[i])) {
+                        if (!(option_mask32 & FLAG(N))) {
+                                fd = open_or_warn(file[i], O_RDONLY);
+                                if (fd == -1)
+                                        goto out;
+                        } else {
+                                /* -N: if some file does not exist compare it like empty */
+                                fd = open(file[i], O_RDONLY);
+                                if (fd == -1)
+                                        fd = xopen("/dev/null", O_RDONLY);
+                        }
+                }
                 /* Our diff implementation is using seek.
                  * When we meet non-seekable file, we must make a temp copy.
                  */
@@ -1010,17 +1009,23 @@ int diff_main(int argc UNUSED_PARAM, char **argv)
         argv += optind;
         while (L_arg)
                 label[!!label[0]] = llist_pop(&L_arg);
+
+        /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
         xfunc_error_retval = 2;
         for (i = 0; i < 2; i++) {
                 file[i] = argv[i];
-                /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
                 if (LONE_DASH(file[i])) {
                         fstat(STDIN_FILENO, &stb[i]);
                         gotstdin++;
-                } else
+                } else if (option_mask32 & FLAG(N)) {
+                        if (stat(file[i], &stb[i]))
+                                xstat("/dev/null", &stb[i]);
+                } else {
                         xstat(file[i], &stb[i]);
+                }
         }
         xfunc_error_retval = 1;
+
         if (gotstdin && (S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode)))
                 bb_error_msg_and_die("can't compare stdin to a directory");
 
diff --git a/editors/sed.c b/editors/sed.c
index 86230ea42..b2c7ba829 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -337,7 +337,7 @@ static int get_address(const char *my_str, int *linenum, regex_t ** regex)
 
         if (isdigit(*my_str)) {
                 *linenum = strtol(my_str, (char**)&pos, 10);
-                /* endstr shouldnt ever equal NULL */
+                /* endstr shouldn't ever equal NULL */
         } else if (*my_str == '$') {
                 *linenum = -1;
                 pos++;
@@ -444,7 +444,7 @@ static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
                         free(fname);
                         break;
                 }
-                /* Ignore case (gnu exension) */
+                /* Ignore case (gnu extension) */
                 case 'i':
                 case 'I':
                         cflags |= REG_ICASE;
@@ -587,7 +587,7 @@ static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
                 free(match);
                 free(replace);
         }
-        /* if it wasnt a single-letter command that takes no arguments
+        /* if it wasn't a single-letter command that takes no arguments
          * then it must be an invalid command.
          */
         else if (idx >= IDX_nul) { /* not d,D,g,G,h,H,l,n,N,p,P,q,x,=,{,} */
@@ -751,7 +751,7 @@ static void do_subst_w_backrefs(char *line, char *replace)
                                 continue;
                         }
                         /* I _think_ it is impossible to get '\' to be
-                         * the last char in replace string. Thus we dont check
+                         * the last char in replace string. Thus we don't check
                          * for replace[i] == NUL. (counterexample anyone?) */
                         /* if we find a backslash escaped character, print the character */
                         pipe_putc(replace[i]);
diff --git a/editors/vi.c b/editors/vi.c
index e5ca3adfa..900b41cb5 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -715,14 +715,6 @@ static int init_text_buffer(char *fn)
 {
         int rc;
 
-        flush_undo_data();
-        modified_count = 0;
-        last_modified_count = -1;
-#if ENABLE_FEATURE_VI_YANKMARK
-        /* init the marks */
-        memset(mark, 0, sizeof(mark));
-#endif
-
         /* allocate/reallocate text buffer */
         free(text);
         text_size = 10240;
@@ -737,6 +729,14 @@ static int init_text_buffer(char *fn)
                 // file doesnt exist. Start empty buf with dummy line
                 char_insert(text, '\n', NO_UNDO);
         }
+
+        flush_undo_data();
+        modified_count = 0;
+        last_modified_count = -1;
+#if ENABLE_FEATURE_VI_YANKMARK
+        /* init the marks */
+        memset(mark, 0, sizeof(mark));
+#endif
         return rc;
 }
 
@@ -1034,7 +1034,9 @@ static void colon(char *buf)
          || strncmp(p, "wn", cnt) == 0
          || (p[0] == 'x' && !p[1])
         ) {
-                cnt = file_write(current_filename, text, end - 1);
+                if (modified_count != 0 || p[0] != 'x') {
+                        cnt = file_write(current_filename, text, end - 1);
+                }
                 if (cnt < 0) {
                         if (cnt == -1)
                                 status_line_bold("Write error: %s", strerror(errno));
@@ -1045,8 +1047,9 @@ static void colon(char *buf)
                                 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'
+                        if (p[0] == 'x'
+                         || p[1] == 'q' || p[1] == 'n'
+                         || p[1] == 'Q' || p[1] == 'N'
                         ) {
                                 editing = 0;
                         }
@@ -1476,16 +1479,19 @@ static void colon(char *buf)
                         goto ret;
                 }
 #endif
-                // how many lines in text[]?
-                li = count_lines(q, r);
-                size = r - q + 1;
                 //if (useforce) {
                         // if "fn" is not write-able, chmod u+w
                         // sprintf(syscmd, "chmod u+w %s", fn);
                         // system(syscmd);
                         // forced = TRUE;
                 //}
-                l = file_write(fn, q, r);
+                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
                         // sprintf(syscmd, "chmod u-w %s", fn);
@@ -1496,17 +1502,20 @@ static void colon(char *buf)
                         if (l == -1)
                                 status_line_bold_errno(fn);
                 } else {
+                        // how many lines written
+                        li = count_lines(q, q + l - 1);
                         status_line("'%s' %dL, %dC", fn, li, l);
-                        if (q == text && r == end - 1 && l == size) {
-                                modified_count = 0;
-                                last_modified_count = -1;
-                        }
-                        if ((cmd[0] == 'x' || cmd[1] == 'q' || cmd[1] == 'n'
-                            || cmd[0] == 'X' || cmd[1] == 'Q' || cmd[1] == 'N'
-                            )
-                         && l == size
-                        ) {
-                                editing = 0;
+                        if (l == size) {
+                                if (q == text && q + l == end) {
+                                        modified_count = 0;
+                                        last_modified_count = -1;
+                                }
+                                if (cmd[0] == 'x'
+                                 || cmd[1] == 'q' || cmd[1] == 'n'
+                                 || cmd[1] == 'Q' || cmd[1] == 'N'
+                                ) {
+                                        editing = 0;
+                                }
                         }
                 }
 #if ENABLE_FEATURE_VI_YANKMARK
@@ -2816,8 +2825,15 @@ static int readit(void) // read (maybe cursor) key from stdin
         int c;
 
         fflush_all();
-        c = read_key(STDIN_FILENO, readbuffer, /*timeout off:*/ -2);
+
+        // Wait for input. TIMEOUT = -1 makes read_key wait even
+        // on nonblocking stdin.
+        // Note: read_key sets errno to 0 on success.
+ again:
+        c = read_key(STDIN_FILENO, readbuffer, /*timeout:*/ -1);
         if (c == -1) { // EOF/error
+                if (errno == EAGAIN) // paranoia
+                        goto again;
                 go_bottom_and_clear_to_eol();
                 cookmode(); // terminal to "cooked"
                 bb_error_msg_and_die("can't read user input");