remote prune: warn dangling symrefs

If you prune from the remote "frotz" that deleted the ref your tracking
branch remotes/frotz/HEAD points at, the symbolic ref will become
dangling.  We used to detect this as an error condition and issued a
message every time refs are enumerated.

This stops the error message, but moves the warning to "remote prune".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-remote.c b/builtin-remote.c
index db18bcf..ac69d37 100644 (file)
--- a/builtin-remote.c
+++ b/builtin-remote.c
@@ -756,12 +756,17 @@ static int prune(int argc, const char **argv)
                OPT_END()
        };
        struct ref_states states;
+       const char *dangling_msg;
 
        argc = parse_options(argc, argv, options, builtin_remote_usage, 0);
 
        if (argc < 1)
                usage_with_options(builtin_remote_usage, options);
 
+       dangling_msg = (dry_run
+                       ? " %s will become dangling!\n"
+                       : " %s has become dangling!\n");
+
        memset(&states, 0, sizeof(states));
        for (; argc; argc--, argv++) {
                int i;
@@ -784,6 +789,7 @@ static int prune(int argc, const char **argv)
 
                        printf(" * [%s] %s\n", dry_run ? "would prune" : "pruned",
                               abbrev_ref(refname, "refs/remotes/"));
+                       warn_dangling_symref(dangling_msg, refname);
                }
 
                /* NEEDSWORK: free remote */

diff --git a/refs.c b/refs.c
index 024211d..6eb5f53 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -275,10 +275,8 @@ static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
                                list = get_ref_dir(ref, list);
                                continue;
                        }
-                       if (!resolve_ref(ref, sha1, 1, &flag)) {
-                               error("%s points nowhere!", ref);
-                               continue;
-                       }
+                       if (!resolve_ref(ref, sha1, 1, &flag))
+                               hashclr(sha1);
                        list = add_ref(ref, sha1, flag, list, NULL);
                }
                free(ref);
@@ -287,6 +285,35 @@ static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
        return sort_ref_list(list);
 }
 
+struct warn_if_dangling_data {
+       const char *refname;
+       const char *msg_fmt;
+};
+
+static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
+                                  int flags, void *cb_data)
+{
+       struct warn_if_dangling_data *d = cb_data;
+       const char *resolves_to;
+       unsigned char junk[20];
+
+       if (!(flags & REF_ISSYMREF))
+               return 0;
+
+       resolves_to = resolve_ref(refname, junk, 0, NULL);
+       if (!resolves_to || strcmp(resolves_to, d->refname))
+               return 0;
+
+       printf(d->msg_fmt, refname);
+       return 0;
+}
+
+void warn_dangling_symref(const char *msg_fmt, const char *refname)
+{
+       struct warn_if_dangling_data data = { refname, msg_fmt };
+       for_each_rawref(warn_if_dangling_symref, &data);
+}
+
 static struct ref_list *get_loose_refs(void)
 {
        if (!cached_refs.did_loose) {
@@ -498,16 +525,19 @@ int read_ref(const char *ref, unsigned char *sha1)
        return -1;
 }
 
+#define DO_FOR_EACH_INCLUDE_BROKEN 01
 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
-                     void *cb_data, struct ref_list *entry)
+                     int flags, void *cb_data, struct ref_list *entry)
 {
        if (strncmp(base, entry->name, trim))
                return 0;
-       if (is_null_sha1(entry->sha1))
-               return 0;
-       if (!has_sha1_file(entry->sha1)) {
-               error("%s does not point to a valid object!", entry->name);
-               return 0;
+       if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
+               if (is_null_sha1(entry->sha1))
+                       return 0;
+               if (!has_sha1_file(entry->sha1)) {
+                       error("%s does not point to a valid object!", entry->name);
+                       return 0;
+               }
        }
        current_ref = entry;
        return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
@@ -561,7 +591,7 @@ fallback:
 }
 
 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
-                          void *cb_data)
+                          int flags, void *cb_data)
 {
        int retval = 0;
        struct ref_list *packed = get_packed_refs();
@@ -570,7 +600,7 @@ static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
        struct ref_list *extra;
 
        for (extra = extra_refs; extra; extra = extra->next)
-               retval = do_one_ref(base, fn, trim, cb_data, extra);
+               retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
 
        while (packed && loose) {
                struct ref_list *entry;
@@ -586,13 +616,13 @@ static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
                        entry = packed;
                        packed = packed->next;
                }
-               retval = do_one_ref(base, fn, trim, cb_data, entry);
+               retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
                if (retval)
                        goto end_each;
        }
 
        for (packed = packed ? packed : loose; packed; packed = packed->next) {
-               retval = do_one_ref(base, fn, trim, cb_data, packed);
+               retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
                if (retval)
                        goto end_each;
        }
@@ -614,22 +644,28 @@ int head_ref(each_ref_fn fn, void *cb_data)
 
 int for_each_ref(each_ref_fn fn, void *cb_data)
 {
-       return do_for_each_ref("refs/", fn, 0, cb_data);
+       return do_for_each_ref("refs/", fn, 0, 0, cb_data);
 }
 
 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 {
-       return do_for_each_ref("refs/tags/", fn, 10, cb_data);
+       return do_for_each_ref("refs/tags/", fn, 10, 0, cb_data);
 }
 
 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 {
-       return do_for_each_ref("refs/heads/", fn, 11, cb_data);
+       return do_for_each_ref("refs/heads/", fn, 11, 0, cb_data);
 }
 
 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 {
-       return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
+       return do_for_each_ref("refs/remotes/", fn, 13, 0, cb_data);
+}
+
+int for_each_rawref(each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref("refs/", fn, 0,
+                              DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
 }
 
 /*

diff --git a/refs.h b/refs.h
index 3bb529d..29bdcec 100644 (file)
--- a/refs.h
+++ b/refs.h
@@ -24,6 +24,11 @@ extern int for_each_tag_ref(each_ref_fn, void *);
 extern int for_each_branch_ref(each_ref_fn, void *);
 extern int for_each_remote_ref(each_ref_fn, void *);
 
+/* can be used to learn about broken ref and symref */
+extern int for_each_rawref(each_ref_fn, void *);
+
+extern void warn_dangling_symref(const char *msg_fmt, const char *refname);
+
 /*
  * Extra refs will be listed by for_each_ref() before any actual refs
  * for the duration of this process or until clear_extra_refs() is

diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index bc5b7ce..2067dc5 100755 (executable)
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -402,4 +402,25 @@ test_expect_success 'migrate a remote from named file in $GIT_DIR/branches' '
         test "$(git config remote.origin.fetch)" = "refs/heads/master:refs/heads/origin")
 '
 
+test_expect_success 'remote prune to cause a dangling symref' '
+       git clone one seven &&
+       (
+               cd one &&
+               git checkout side2 &&
+               git branch -D master
+       ) &&
+       (
+               cd seven &&
+               git remote prune origin
+       ) 2>err &&
+       grep "has become dangling" err &&
+
+       : And the dangling symref will not cause other annoying errors
+       (
+               cd seven &&
+               git branch -a
+       ) 2>err &&
+       ! grep "points nowhere" err
+'
+
 test_done