]> git.ipfire.org Git - thirdparty/git.git/blobdiff - path.c
Fix GIT_CEILING_DIRECTORIES on Windows
[thirdparty/git.git] / path.c
diff --git a/path.c b/path.c
index c1d567996d225c03f58c1208f4806f74f64e92e1..79c5c104c3718a71a0dab40cb2b8a0a8a974dabf 100644 (file)
--- a/path.c
+++ b/path.c
@@ -32,6 +32,60 @@ static char *cleanup_path(char *path)
        return path;
 }
 
+char *mksnpath(char *buf, size_t n, const char *fmt, ...)
+{
+       va_list args;
+       unsigned len;
+
+       va_start(args, fmt);
+       len = vsnprintf(buf, n, fmt, args);
+       va_end(args);
+       if (len >= n) {
+               strlcpy(buf, bad_path, n);
+               return buf;
+       }
+       return cleanup_path(buf);
+}
+
+static char *git_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
+{
+       const char *git_dir = get_git_dir();
+       size_t len;
+
+       len = strlen(git_dir);
+       if (n < len + 1)
+               goto bad;
+       memcpy(buf, git_dir, len);
+       if (len && !is_dir_sep(git_dir[len-1]))
+               buf[len++] = '/';
+       len += vsnprintf(buf + len, n - len, fmt, args);
+       if (len >= n)
+               goto bad;
+       return cleanup_path(buf);
+bad:
+       strlcpy(buf, bad_path, n);
+       return buf;
+}
+
+char *git_snpath(char *buf, size_t n, const char *fmt, ...)
+{
+       va_list args;
+       va_start(args, fmt);
+       (void)git_vsnpath(buf, n, fmt, args);
+       va_end(args);
+       return buf;
+}
+
+char *git_pathdup(const char *fmt, ...)
+{
+       char path[PATH_MAX];
+       va_list args;
+       va_start(args, fmt);
+       (void)git_vsnpath(path, sizeof(path), fmt, args);
+       va_end(args);
+       return xstrdup(path);
+}
+
 char *mkpath(const char *fmt, ...)
 {
        va_list args;
@@ -291,45 +345,6 @@ int adjust_shared_perm(const char *path)
        return 0;
 }
 
-static const char *get_pwd_cwd(void)
-{
-       static char cwd[PATH_MAX + 1];
-       char *pwd;
-       struct stat cwd_stat, pwd_stat;
-       if (getcwd(cwd, PATH_MAX) == NULL)
-               return NULL;
-       pwd = getenv("PWD");
-       if (pwd && strcmp(pwd, cwd)) {
-               stat(cwd, &cwd_stat);
-               if (!stat(pwd, &pwd_stat) &&
-                   pwd_stat.st_dev == cwd_stat.st_dev &&
-                   pwd_stat.st_ino == cwd_stat.st_ino) {
-                       strlcpy(cwd, pwd, PATH_MAX);
-               }
-       }
-       return cwd;
-}
-
-const char *make_nonrelative_path(const char *path)
-{
-       static char buf[PATH_MAX + 1];
-
-       if (is_absolute_path(path)) {
-               if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
-                       die ("Too long path: %.*s", 60, path);
-       } else {
-               const char *cwd = get_pwd_cwd();
-               if (!cwd)
-                       die("Cannot determine the current working directory");
-               if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
-                       die ("Too long path: %.*s", 60, path);
-       }
-       return buf;
-}
-
-/* We allow "recursive" symbolic links. Only within reason, though. */
-#define MAXDEPTH 5
-
 const char *make_relative_path(const char *abs, const char *base)
 {
        static char buf[PATH_MAX + 1];
@@ -347,66 +362,185 @@ const char *make_relative_path(const char *abs, const char *base)
        return buf;
 }
 
-const char *make_absolute_path(const char *path)
+/*
+ * path = absolute path
+ * buf = buffer of at least max(2, strlen(path)+1) bytes
+ * It is okay if buf == path, but they should not overlap otherwise.
+ *
+ * Performs the following normalizations on path, storing the result in buf:
+ * - Removes trailing slashes.
+ * - Removes empty components.
+ * - Removes "." components.
+ * - Removes ".." components, and the components the precede them.
+ * "" and paths that contain only slashes are normalized to "/".
+ * Returns the length of the output.
+ *
+ * Note that this function is purely textual.  It does not follow symlinks,
+ * verify the existence of the path, or make any system calls.
+ */
+int normalize_absolute_path(char *buf, const char *path)
 {
-       static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
-       char cwd[1024] = "";
-       int buf_index = 1, len;
+       const char *comp_start = path, *comp_end = path;
+       char *dst = buf;
+       int comp_len;
+       assert(buf);
+       assert(path);
+
+       while (*comp_start) {
+               assert(*comp_start == '/');
+               while (*++comp_end && *comp_end != '/')
+                       ; /* nothing */
+               comp_len = comp_end - comp_start;
+
+               if (!strncmp("/",  comp_start, comp_len) ||
+                   !strncmp("/.", comp_start, comp_len))
+                       goto next;
+
+               if (!strncmp("/..", comp_start, comp_len)) {
+                       while (dst > buf && *--dst != '/')
+                               ; /* nothing */
+                       goto next;
+               }
 
-       int depth = MAXDEPTH;
-       char *last_elem = NULL;
-       struct stat st;
+               memmove(dst, comp_start, comp_len);
+               dst += comp_len;
+       next:
+               comp_start = comp_end;
+       }
 
-       if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
-               die ("Too long path: %.*s", 60, path);
-
-       while (depth--) {
-               if (stat(buf, &st) || !S_ISDIR(st.st_mode)) {
-                       char *last_slash = strrchr(buf, '/');
-                       if (last_slash) {
-                               *last_slash = '\0';
-                               last_elem = xstrdup(last_slash + 1);
-                       } else {
-                               last_elem = xstrdup(buf);
-                               *buf = '\0';
-                       }
-               }
+       if (dst == buf)
+               *dst++ = '/';
+
+       *dst = '\0';
+       return dst - buf;
+}
 
-               if (*buf) {
-                       if (!*cwd && !getcwd(cwd, sizeof(cwd)))
-                               die ("Could not get current working directory");
+int normalize_path_copy(char *dst, const char *src)
+{
+       char *dst0;
 
-                       if (chdir(buf))
-                               die ("Could not switch to '%s'", buf);
-               }
-               if (!getcwd(buf, PATH_MAX))
-                       die ("Could not get current working directory");
-
-               if (last_elem) {
-                       int len = strlen(buf);
-                       if (len + strlen(last_elem) + 2 > PATH_MAX)
-                               die ("Too long path name: '%s/%s'",
-                                               buf, last_elem);
-                       buf[len] = '/';
-                       strcpy(buf + len + 1, last_elem);
-                       free(last_elem);
-                       last_elem = NULL;
+       if (has_dos_drive_prefix(src)) {
+               *dst++ = *src++;
+               *dst++ = *src++;
+       }
+       dst0 = dst;
+
+       if (is_dir_sep(*src)) {
+               *dst++ = '/';
+               while (is_dir_sep(*src))
+                       src++;
+       }
+
+       for (;;) {
+               char c = *src;
+
+               /*
+                * A path component that begins with . could be
+                * special:
+                * (1) "." and ends   -- ignore and terminate.
+                * (2) "./"           -- ignore them, eat slash and continue.
+                * (3) ".." and ends  -- strip one and terminate.
+                * (4) "../"          -- strip one, eat slash and continue.
+                */
+               if (c == '.') {
+                       if (!src[1]) {
+                               /* (1) */
+                               src++;
+                       } else if (is_dir_sep(src[1])) {
+                               /* (2) */
+                               src += 2;
+                               while (is_dir_sep(*src))
+                                       src++;
+                               continue;
+                       } else if (src[1] == '.') {
+                               if (!src[2]) {
+                                       /* (3) */
+                                       src += 2;
+                                       goto up_one;
+                               } else if (is_dir_sep(src[2])) {
+                                       /* (4) */
+                                       src += 3;
+                                       while (is_dir_sep(*src))
+                                               src++;
+                                       goto up_one;
+                               }
+                       }
                }
 
-               if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
-                       len = readlink(buf, next_buf, PATH_MAX);
-                       if (len < 0)
-                               die ("Invalid symlink: %s", buf);
-                       next_buf[len] = '\0';
-                       buf = next_buf;
-                       buf_index = 1 - buf_index;
-                       next_buf = bufs[buf_index];
-               } else
+               /* copy up to the next '/', and eat all '/' */
+               while ((c = *src++) != '\0' && !is_dir_sep(c))
+                       *dst++ = c;
+               if (is_dir_sep(c)) {
+                       *dst++ = '/';
+                       while (is_dir_sep(c))
+                               c = *src++;
+                       src--;
+               } else if (!c)
                        break;
+               continue;
+
+       up_one:
+               /*
+                * dst0..dst is prefix portion, and dst[-1] is '/';
+                * go up one level.
+                */
+               dst -= 2; /* go past trailing '/' if any */
+               if (dst < dst0)
+                       return -1;
+               while (1) {
+                       if (dst <= dst0)
+                               break;
+                       c = *dst--;
+                       if (c == '/') { /* MinGW: cannot be '\\' anymore */
+                               dst += 2;
+                               break;
+                       }
+               }
        }
+       *dst = '\0';
+       return 0;
+}
 
-       if (*cwd && chdir(cwd))
-               die ("Could not change back to '%s'", cwd);
+/*
+ * path = Canonical absolute path
+ * prefix_list = Colon-separated list of absolute paths
+ *
+ * Determines, for each path in prefix_list, whether the "prefix" really
+ * is an ancestor directory of path.  Returns the length of the longest
+ * ancestor directory, excluding any trailing slashes, or -1 if no prefix
+ * is an ancestor.  (Note that this means 0 is returned if prefix_list is
+ * "/".) "/foo" is not considered an ancestor of "/foobar".  Directories
+ * are not considered to be their own ancestors.  path must be in a
+ * canonical form: empty components, or "." or ".." components are not
+ * allowed.  prefix_list may be null, which is like "".
+ */
+int longest_ancestor_length(const char *path, const char *prefix_list)
+{
+       char buf[PATH_MAX+1];
+       const char *ceil, *colon;
+       int len, max_len = -1;
 
-       return buf;
+       if (prefix_list == NULL || !strcmp(path, "/"))
+               return -1;
+
+       for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
+               for (colon = ceil; *colon && *colon != PATH_SEP; colon++);
+               len = colon - ceil;
+               if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
+                       continue;
+               strlcpy(buf, ceil, len+1);
+               if (normalize_path_copy(buf, buf) < 0)
+                       continue;
+               len = strlen(buf);
+               if (len > 0 && buf[len-1] == '/')
+                       buf[--len] = '\0';
+
+               if (!strncmp(path, buf, len) &&
+                   path[len] == '/' &&
+                   len > max_len) {
+                       max_len = len;
+               }
+       }
+
+       return max_len;
 }