Merge git://repo.or.cz/git-gui

[git.git] / refs.c

diff --git a/refs.c b/refs.c
index 39a3b23804d2da715c564459bf320be23d41c1bf..0a126fa371ae24f5cb251ff52cf7d38322d78ba7 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -390,6 +390,18 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *re
        return retval;
 }
 
+/*
+ * If the "reading" argument is set, this function finds out what _object_
+ * the ref points at by "reading" the ref.  The ref, if it is not symbolic,
+ * has to exist, and if it is symbolic, it has to point at an existing ref,
+ * because the "read" goes through the symref to the ref it points at.
+ *
+ * The access that is not "reading" may often be "writing", but does not
+ * have to; it can be merely checking _where it leads to_. If it is a
+ * prelude to "writing" to the ref, a write to a symref that points at
+ * yet-to-be-born ref will create the real ref pointed by the symref.
+ * reading=0 allows the caller to check where such a symref leads to.
+ */
 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
 {
        int depth = MAXDEPTH;
@@ -409,13 +421,7 @@ const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *
                if (--depth < 0)
                        return NULL;
 
-               /* Special case: non-existing file.
-                * Not having the refs/heads/new-branch is OK
-                * if we are writing into it, so is .git/HEAD
-                * that points at refs/heads/master still to be
-                * born.  It is NOT OK if we are resolving for
-                * reading.
-                */
+               /* Special case: non-existing file. */
                if (lstat(path, &st) < 0) {
                        struct ref_list *list = get_packed_refs();
                        while (list) {
@@ -790,7 +796,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
        struct ref_lock *lock;
        struct stat st;
        int last_errno = 0;
-       int type;
+       int type, lflags;
        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 
        lock = xcalloc(1, sizeof(struct ref_lock));
@@ -830,8 +836,11 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
 
        lock->lk = xcalloc(1, sizeof(struct lock_file));
 
-       if (flags & REF_NODEREF)
+       lflags = LOCK_DIE_ON_ERROR;
+       if (flags & REF_NODEREF) {
                ref = orig_ref;
+               lflags |= LOCK_NODEREF;
+       }
        lock->ref_name = xstrdup(ref);
        lock->orig_ref_name = xstrdup(orig_ref);
        ref_file = git_path("%s", ref);
@@ -845,8 +854,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
                error("unable to create directory for %s", ref_file);
                goto error_return;
        }
-       lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
 
+       lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
        return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 
  error_return: