tree-diff: allow diff_tree_sha1 to accept NULL sha1

diff --git a/refs.c b/refs.c
index 490b57b881d88f3f88b11327b20d19f6f3938c46..89228e23732ef7e2e83a2e84e82ffb5bd7afec3f 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -1880,7 +1880,7 @@ const char *prettify_refname(const char *name)
                0);
 }
 
-const char *ref_rev_parse_rules[] = {
+static const char *ref_rev_parse_rules[] = {
        "%.*s",
        "refs/%.*s",
        "refs/tags/%.*s",
@@ -1890,12 +1890,12 @@ const char *ref_rev_parse_rules[] = {
        NULL
 };
 
-int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
+int refname_match(const char *abbrev_name, const char *full_name)
 {
        const char **p;
        const int abbrev_name_len = strlen(abbrev_name);
 
-       for (p = rules; *p; p++) {
+       for (p = ref_rev_parse_rules; *p; p++) {
                if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
                        return 1;
                }
@@ -2039,6 +2039,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
        int type, lflags;
        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
        int missing = 0;
+       int attempts_remaining = 3;
 
        lock = xcalloc(1, sizeof(struct ref_lock));
        lock->lock_fd = -1;
@@ -2080,7 +2081,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 
        lock->lk = xcalloc(1, sizeof(struct lock_file));
 
-       lflags = LOCK_DIE_ON_ERROR;
+       lflags = 0;
        if (flags & REF_NODEREF) {
                refname = orig_refname;
                lflags |= LOCK_NODEREF;
@@ -2093,13 +2094,32 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
        if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
                lock->force_write = 1;
 
-       if (safe_create_leading_directories(ref_file)) {
+ retry:
+       switch (safe_create_leading_directories(ref_file)) {
+       case SCLD_OK:
+               break; /* success */
+       case SCLD_VANISHED:
+               if (--attempts_remaining > 0)
+                       goto retry;
+               /* fall through */
+       default:
                last_errno = errno;
                error("unable to create directory for %s", ref_file);
                goto error_return;
        }
 
        lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
+       if (lock->lock_fd < 0) {
+               if (errno == ENOENT && --attempts_remaining > 0)
+                       /*
+                        * Maybe somebody just deleted one of the
+                        * directories leading to ref_file.  Try
+                        * again:
+                        */
+                       goto retry;
+               else
+                       unable_to_lock_index_die(ref_file, errno);
+       }
        return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 
  error_return:
@@ -2508,6 +2528,51 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
  */
 #define TMP_RENAMED_LOG  "logs/refs/.tmp-renamed-log"
 
+static int rename_tmp_log(const char *newrefname)
+{
+       int attempts_remaining = 4;
+
+ retry:
+       switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
+       case SCLD_OK:
+               break; /* success */
+       case SCLD_VANISHED:
+               if (--attempts_remaining > 0)
+                       goto retry;
+               /* fall through */
+       default:
+               error("unable to create directory for %s", newrefname);
+               return -1;
+       }
+
+       if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
+               if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
+                       /*
+                        * rename(a, b) when b is an existing
+                        * directory ought to result in ISDIR, but
+                        * Solaris 5.8 gives ENOTDIR.  Sheesh.
+                        */
+                       if (remove_empty_directories(git_path("logs/%s", newrefname))) {
+                               error("Directory not empty: logs/%s", newrefname);
+                               return -1;
+                       }
+                       goto retry;
+               } else if (errno == ENOENT && --attempts_remaining > 0) {
+                       /*
+                        * Maybe another process just deleted one of
+                        * the directories in the path to newrefname.
+                        * Try again from the beginning.
+                        */
+                       goto retry;
+               } else {
+                       error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
+                               newrefname, strerror(errno));
+                       return -1;
+               }
+       }
+       return 0;
+}
+
 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
 {
        unsigned char sha1[20], orig_sha1[20];
@@ -2555,30 +2620,9 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
                }
        }
 
-       if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
-               error("unable to create directory for %s", newrefname);
+       if (log && rename_tmp_log(newrefname))
                goto rollback;
-       }
 
- retry:
-       if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
-               if (errno==EISDIR || errno==ENOTDIR) {
-                       /*
-                        * rename(a, b) when b is an existing
-                        * directory ought to result in ISDIR, but
-                        * Solaris 5.8 gives ENOTDIR.  Sheesh.
-                        */
-                       if (remove_empty_directories(git_path("logs/%s", newrefname))) {
-                               error("Directory not empty: logs/%s", newrefname);
-                               goto rollback;
-                       }
-                       goto retry;
-               } else {
-                       error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
-                               newrefname, strerror(errno));
-                       goto rollback;
-               }
-       }
        logmoved = log;
 
        lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);