Tighten refspec processing

diff --git a/path.c b/path.c
index d2c076d7cbad3a16a002897d926cc13633be4f77..f4ed979997b6a968ba1987a199beae39035d5da2 100644 (file)
--- a/path.c
+++ b/path.c
@@ -11,7 +11,6 @@
  * which is what it's designed for.
  */
 #include "cache.h"
-#include <pwd.h>
 
 static char bad_path[] = "/bad-path/";
 
@@ -72,29 +71,26 @@ char *git_path(const char *fmt, ...)
 /* git_mkstemp() - create tmp file honoring TMPDIR variable */
 int git_mkstemp(char *path, size_t len, const char *template)
 {
-       char *env, *pch = path;
+       const char *tmp;
+       size_t n;
 
-       if ((env = getenv("TMPDIR")) == NULL) {
-               strcpy(pch, "/tmp/");
-               len -= 5;
-               pch += 5;
-       } else {
-               size_t n = snprintf(pch, len, "%s/", env);
-
-               len -= n;
-               pch += n;
+       tmp = getenv("TMPDIR");
+       if (!tmp)
+               tmp = "/tmp";
+       n = snprintf(path, len, "%s/%s", tmp, template);
+       if (len <= n) {
+               errno = ENAMETOOLONG;
+               return -1;
        }
-
-       strlcpy(pch, template, len);
-
        return mkstemp(path);
 }
 
 
-int validate_symref(const char *path)
+int validate_headref(const char *path)
 {
        struct stat st;
        char *buf, buffer[256];
+       unsigned char sha1[20];
        int len, fd;
 
        if (lstat(path, &st) < 0)
@@ -114,20 +110,29 @@ int validate_symref(const char *path)
        fd = open(path, O_RDONLY);
        if (fd < 0)
                return -1;
-       len = read(fd, buffer, sizeof(buffer)-1);
+       len = read_in_full(fd, buffer, sizeof(buffer)-1);
        close(fd);
 
        /*
         * Is it a symbolic ref?
         */
-       if (len < 4 || memcmp("ref:", buffer, 4))
+       if (len < 4)
                return -1;
-       buf = buffer + 4;
-       len -= 4;
-       while (len && isspace(*buf))
-               buf++, len--;
-       if (len >= 5 && !memcmp("refs/", buf, 5))
+       if (!memcmp("ref:", buffer, 4)) {
+               buf = buffer + 4;
+               len -= 4;
+               while (len && isspace(*buf))
+                       buf++, len--;
+               if (len >= 5 && !memcmp("refs/", buf, 5))
+                       return 0;
+       }
+
+       /*
+        * Is this a detached HEAD?
+        */
+       if (!get_sha1_hex(buffer, sha1))
                return 0;
+
        return -1;
 }
 
@@ -242,8 +247,8 @@ char *enter_repo(char *path, int strict)
                return NULL;
 
        if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
-           validate_symref("HEAD") == 0) {
-               putenv("GIT_DIR=.");
+           validate_headref("HEAD") == 0) {
+               setenv(GIT_DIR_ENVIRONMENT, ".", 1);
                check_repository_format();
                return path;
        }
@@ -278,8 +283,75 @@ int adjust_shared_perm(const char *path)
                            ? (S_IXGRP|S_IXOTH)
                            : 0));
        if (S_ISDIR(mode))
-               mode |= S_ISGID;
+               mode |= FORCE_DIR_SET_GID;
        if ((mode & st.st_mode) != mode && chmod(path, mode) < 0)
                return -2;
        return 0;
 }
+
+/* We allow "recursive" symbolic links. Only within reason, though. */
+#define MAXDEPTH 5
+
+const char *make_absolute_path(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;
+
+       int depth = MAXDEPTH;
+       char *last_elem = NULL;
+       struct stat st;
+
+       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 (*buf) {
+                       if (!*cwd && !getcwd(cwd, sizeof(cwd)))
+                               die ("Could not get current working directory");
+
+                       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 (!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
+                       break;
+       }
+
+       if (*cwd && chdir(cwd))
+               die ("Could not change back to '%s'", cwd);
+
+       return buf;
+}