abspath: convert real_path_internal() to strbuf

Use strbuf instead of fixed-sized buffers in real_path() in order to
avoid the size limitations of the latter.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/abspath.c b/abspath.c
index 911e931cc07118b9a696bd6ae041485a8eae3c0a..6aa328f805fe1b0074e4e173effd97386218b923 100644 (file)
--- a/abspath.c
+++ b/abspath.c
@@ -33,7 +33,7 @@ int is_directory(const char *path)
  */
 static const char *real_path_internal(const char *path, int die_on_error)
 {
-       static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
+       static struct strbuf sb = STRBUF_INIT;
        char *retval = NULL;
 
        /*
@@ -43,14 +43,12 @@ static const char *real_path_internal(const char *path, int die_on_error)
         */
        struct strbuf cwd = STRBUF_INIT;
 
-       int buf_index = 1;
-
        int depth = MAXDEPTH;
        char *last_elem = NULL;
        struct stat st;
 
        /* We've already done it */
-       if (path == buf || path == next_buf)
+       if (path == sb.buf)
                return path;
 
        if (!*path) {
@@ -60,26 +58,22 @@ static const char *real_path_internal(const char *path, int die_on_error)
                        goto error_out;
        }
 
-       if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX) {
-               if (die_on_error)
-                       die("Too long path: %.*s", 60, path);
-               else
-                       goto error_out;
-       }
+       strbuf_reset(&sb);
+       strbuf_addstr(&sb, path);
 
        while (depth--) {
-               if (!is_directory(buf)) {
-                       char *last_slash = find_last_dir_sep(buf);
+               if (!is_directory(sb.buf)) {
+                       char *last_slash = find_last_dir_sep(sb.buf);
                        if (last_slash) {
                                last_elem = xstrdup(last_slash + 1);
-                               last_slash[1] = '\0';
+                               strbuf_setlen(&sb, last_slash - sb.buf + 1);
                        } else {
-                               last_elem = xstrdup(buf);
-                               *buf = '\0';
+                               last_elem = xmemdupz(sb.buf, sb.len);
+                               strbuf_reset(&sb);
                        }
                }
 
-               if (*buf) {
+               if (sb.len) {
                        if (!cwd.len && strbuf_getcwd(&cwd)) {
                                if (die_on_error)
                                        die_errno("Could not get current working directory");
@@ -87,14 +81,15 @@ static const char *real_path_internal(const char *path, int die_on_error)
                                        goto error_out;
                        }
 
-                       if (chdir(buf)) {
+                       if (chdir(sb.buf)) {
                                if (die_on_error)
-                                       die_errno("Could not switch to '%s'", buf);
+                                       die_errno("Could not switch to '%s'",
+                                                 sb.buf);
                                else
                                        goto error_out;
                        }
                }
-               if (!getcwd(buf, PATH_MAX)) {
+               if (strbuf_getcwd(&sb)) {
                        if (die_on_error)
                                die_errno("Could not get current working directory");
                        else
@@ -102,44 +97,30 @@ static const char *real_path_internal(const char *path, int die_on_error)
                }
 
                if (last_elem) {
-                       size_t len = strlen(buf);
-                       if (len + strlen(last_elem) + 2 > PATH_MAX) {
-                               if (die_on_error)
-                                       die("Too long path name: '%s/%s'",
-                                           buf, last_elem);
-                               else
-                                       goto error_out;
-                       }
-                       if (len && !is_dir_sep(buf[len - 1]))
-                               buf[len++] = '/';
-                       strcpy(buf + len, last_elem);
+                       if (sb.len && !is_dir_sep(sb.buf[sb.len - 1]))
+                               strbuf_addch(&sb, '/');
+                       strbuf_addstr(&sb, last_elem);
                        free(last_elem);
                        last_elem = NULL;
                }
 
-               if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
-                       ssize_t len = readlink(buf, next_buf, PATH_MAX);
+               if (!lstat(sb.buf, &st) && S_ISLNK(st.st_mode)) {
+                       struct strbuf next_sb = STRBUF_INIT;
+                       ssize_t len = strbuf_readlink(&next_sb, sb.buf, 0);
                        if (len < 0) {
                                if (die_on_error)
-                                       die_errno("Invalid symlink '%s'", buf);
-                               else
-                                       goto error_out;
-                       }
-                       if (PATH_MAX <= len) {
-                               if (die_on_error)
-                                       die("symbolic link too long: %s", buf);
+                                       die_errno("Invalid symlink '%s'",
+                                                 sb.buf);
                                else
                                        goto error_out;
                        }
-                       next_buf[len] = '\0';
-                       buf = next_buf;
-                       buf_index = 1 - buf_index;
-                       next_buf = bufs[buf_index];
+                       strbuf_swap(&sb, &next_sb);
+                       strbuf_release(&next_sb);
                } else
                        break;
        }
 
-       retval = buf;
+       retval = sb.buf;
 error_out:
        free(last_elem);
        if (cwd.len && chdir(cwd.buf))