Fix "git add -u" data corruption.

diff --git a/path.c b/path.c
index db8905f3c352592124b2f0bda18fc0ccd048528e..6395cf23098841c16d993ae7e86b2d8dcff01cd7 100644 (file)
--- a/path.c
+++ b/path.c
@@ -11,11 +11,16 @@
  * which is what it's designed for.
  */
 #include "cache.h"
-#include <pwd.h>
 
-static char pathname[PATH_MAX];
 static char bad_path[] = "/bad-path/";
 
+static char *get_pathname(void)
+{
+       static char pathname_array[4][PATH_MAX];
+       static int index;
+       return pathname_array[3 & ++index];
+}
+
 static char *cleanup_path(char *path)
 {
        /* Clean it up */
@@ -31,6 +36,7 @@ char *mkpath(const char *fmt, ...)
 {
        va_list args;
        unsigned len;
+       char *pathname = get_pathname();
 
        va_start(args, fmt);
        len = vsnprintf(pathname, PATH_MAX, fmt, args);
@@ -43,6 +49,7 @@ char *mkpath(const char *fmt, ...)
 char *git_path(const char *fmt, ...)
 {
        const char *git_dir = get_git_dir();
+       char *pathname = get_pathname();
        va_list args;
        unsigned len;
 
@@ -83,10 +90,11 @@ int git_mkstemp(char *path, size_t len, const char *template)
 }
 
 
-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)
@@ -106,20 +114,29 @@ 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;
 }
 
@@ -234,8 +251,8 @@ 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", ".", 1);
                check_repository_format();
                return path;
        }
@@ -271,7 +288,7 @@ int adjust_shared_perm(const char *path)
                            : 0));
        if (S_ISDIR(mode))
                mode |= S_ISGID;
-       if (chmod(path, mode) < 0)
+       if ((mode & st.st_mode) != mode && chmod(path, mode) < 0)
                return -2;
        return 0;
 }