show-branch: show all local heads when only giving one rev along --topics

"git show-branch --topics <rev> <revs>..." displays ancestry graph, only
considering commits that are in all given revs, except the first one.

"git show-branch" displays ancestry graph for all local branches.

Unfortunately, "git show-branch --topics <rev>" only prints out the rev
info for the given rev, and nothing else, e.g.:

$ git show-branch --topics origin/master
[origin/master] Sync with 2.3.3

While there is an option to add all remote-tracking branches (-r), and
another to add all local+remote branches (-a), there is no option to add
only local branches. Adding such an option could be considered, but a
user would likely already expect that the above command line considers
the lack of rev other than for --topics as meaning all local branches,
like when there is no argument at all.

Moreover, when using -r and -a along with --topics, the first local or
remote-tracking branch, depending on alphabetic order is used instead of
the one given after --topics (any rev given on the command line is
actually simply ignored when either -r or -a is given). And if no rev is
given at all, the fact that the first alphetical branch is the base of
topics is probably not expected by users (Maybe --topics should always
require one rev on the command line?)

This change makes
"show-branch --topics $rev"
act as
"show-branch --topics $rev $(git for-each-ref refs/heads
--format='%(refname:short)')"

"show-branch -r --topics $rev ..."
act as
"show-branch --topics $rev ... $(git for-each-ref refs/remotes
--format='%(refname:short)')"
instead of
"show-branch --topics $(git for-each-ref refs/remotes
--format='%(refname:short)')"

and
"show-branch -a --topics $rev ..."
act as
"show-branch --topics $rev ... $(git for-each-ref refs/heads refs/remotes
--format='%(refname:short)')"
instead of
"show-branch --topics $(git for-each-ref refs/heads refs/remotes
--format='%(refname:short)')"

Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 365228aa8d805bdf86a6eecccdc088068ba000d2..ef9e719b0f5be5c82d564d247ea4467ff9f3a030 100644 (file)
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -718,7 +718,7 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
        }
 
        /* If nothing is specified, show all branches by default */
-       if (ac + all_heads + all_remotes == 0)
+       if (ac <= topics && all_heads + all_remotes == 0)
                all_heads = 1;
 
        if (reflog) {
@@ -785,13 +785,13 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
                }
                free(ref);
        }
-       else if (all_heads + all_remotes)
-               snarf_refs(all_heads, all_remotes);
        else {
                while (0 < ac) {
                        append_one_rev(*av);
                        ac--; av++;
                }
+               if (all_heads + all_remotes)
+                       snarf_refs(all_heads, all_remotes);
        }
 
        head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,