[RFC 06/11] fetch --prune: allow refname patterns to be specified

[Michael Haggerty <mhagger@alum.mit.edu>]

Allow optional arguments to be passed to "git fetch --prune" to choose
which references are subject to pruning.  The default, if no argument
is specified, is to prune all references as before.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 Documentation/fetch-options.txt |  6 +++++-
 builtin/fetch.c                 |  8 ++++++--
 t/t5510-fetch.sh                | 12 ++++++++++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt
index f0ef7d0..61d3f75 100644
--- a/Documentation/fetch-options.txt
+++ b/Documentation/fetch-options.txt
@@ -40,7 +40,7 @@ ifndef::git-pull[]
 	specified. No <refspec>s may be specified.
 
 -p::
---prune::
+--prune[=<pattern>]::
 	After fetching, remove any remote-tracking references that no
 	longer exist on the remote.  Tags are not subject to pruning
 	if they are fetched only because of the default tag
@@ -49,6 +49,10 @@ ifndef::git-pull[]
 	line or in the remote configuration, for example if the remote
 	was cloned with the --mirror option), then they are also
 	subject to pruning.
++
+If pattern is specified, then it should be a glob pattern, and pruning
+is further restricted to references whose names match the pattern.
+This option can be specified multiple times.
 endif::git-pull[]
 
 ifndef::git-pull[]
diff --git a/builtin/fetch.c b/builtin/fetch.c
index fcc06a4..2cb48a6 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -73,9 +73,12 @@ static struct option builtin_fetch_options[] = {
 		    N_("fetch all tags and associated objects"), TAGS_SET),
 	OPT_SET_INT('n', NULL, &tags,
 		    N_("do not fetch all tags (--no-tags)"), TAGS_UNSET),
-	{ OPTION_CALLBACK, 'p', "prune", &prune_option, N_("pattern"),
+	{ OPTION_CALLBACK, 'p', NULL, &prune_option, NULL,
 		    N_("prune remote-tracking branches no longer on remote"),
 		    PARSE_OPT_NOARG, prune_option_parse },
+	{ OPTION_CALLBACK, 0, "prune", &prune_option, N_("pattern"),
+		    N_("prune remote-tracking branches (matching pattern, if specified)"),
+		    PARSE_OPT_OPTARG, prune_option_parse },
 	{ OPTION_CALLBACK, 0, "recurse-submodules", NULL, N_("on-demand"),
 		    N_("control recursive fetching of submodules"),
 		    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
@@ -702,7 +705,8 @@ static int fetch_refs(struct transport *transport, struct ref *ref_map)
 static int prune_refs(struct refspec *refs, int ref_count, struct ref *ref_map)
 {
 	int result = 0;
-	struct ref *stale_refs = get_stale_heads(refs, ref_count, ref_map, NULL);
+	struct ref *stale_refs = get_stale_heads(refs, ref_count, ref_map,
+						 &prune_option.prune_patterns);
 	struct ref *ref;
 	const char *dangling_msg = dry_run
 		? _("   (%s will become dangling)")
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index 5d4581d..42eb21f 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -94,6 +94,18 @@ test_expect_success 'fetch --prune on its own works as expected' '
 	test_must_fail git rev-parse origin/extrabranch
 '
 
+test_expect_success 'fetch --prune with arguments' '
+	cd "$D" &&
+	git clone . prune-args &&
+	cd prune-args &&
+	git update-ref refs/remotes/origin/branch1 master &&
+	git update-ref refs/remotes/origin/branch2 master &&
+
+	git fetch --prune="refs/remotes/origin/*1" origin &&
+	test_must_fail git rev-parse origin/branch1 &&
+	git rev-parse origin/branch2
+'
+
 test_expect_success 'fetch --prune with a branch name keeps branches' '
 	cd "$D" &&
 	git clone . prune-branch &&
-- 
1.8.4.3