fetch: make --prune configurablems/fetch-prune-configuration

Without "git fetch --prune", remote-tracking branches for a branch
the other side already has removed will stay forever.  Some people
want to always run "git fetch --prune".

To accommodate users who want to either prune always or when fetching
from a particular remote, add two new configuration variables
"fetch.prune" and "remote.<name>.prune":

 - "fetch.prune" allows to enable prune for all fetch operations.

 - "remote.<name>.prune" allows to change the behaviour per remote.

The latter will naturally override the former, and the --[no-]prune
option from the command line will override the configured default.

Since --prune is a potentially destructive operation (Git doesn't
keep reflogs for deleted references yet), we don't want to prune
without users consent, so this configuration will not be on by
default.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 34 insertions, 5 deletions

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 4b6b1dfe66..08ab948022 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -30,7 +30,11 @@ enum {
 	TAGS_SET = 2
 };
 
-static int all, append, dry_run, force, keep, multiple, prune, update_head_ok, verbosity;
+static int fetch_prune_config = -1; /* unspecified */
+static int prune = -1; /* unspecified */
+#define PRUNE_BY_DEFAULT 0 /* do we prune by default? */
+
+static int all, append, dry_run, force, keep, multiple, update_head_ok, verbosity;
 static int progress = -1, recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
 static int tags = TAGS_DEFAULT, unshallow;
 static const char *depth;
@@ -54,6 +58,15 @@ static int option_parse_recurse_submodules(const struct option *opt,
 	return 0;
 }
 
+static int git_fetch_config(const char *k, const char *v, void *cb)
+{
+	if (!strcmp(k, "fetch.prune")) {
+		fetch_prune_config = git_config_bool(k, v);
+		return 0;
+	}
+	return 0;
+}
+
 static struct option builtin_fetch_options[] = {
 	OPT__VERBOSITY(&verbosity),
 	OPT_BOOLEAN(0, "all", &all,
@@ -69,8 +82,8 @@ 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),
-	OPT_BOOLEAN('p', "prune", &prune,
-		    N_("prune remote-tracking branches no longer on remote")),
+	OPT_BOOL('p', "prune", &prune,
+		 N_("prune remote-tracking branches no longer on remote")),
 	{ OPTION_CALLBACK, 0, "recurse-submodules", NULL, N_("on-demand"),
 		    N_("control recursive fetching of submodules"),
 		    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
@@ -739,7 +752,10 @@ static int do_fetch(struct transport *transport,
 		return 1;
 	}
 	if (prune) {
-		/* If --tags was specified, pretend the user gave us the canonical tags refspec */
+		/*
+		 * If --tags was specified, pretend that the user gave us
+		 * the canonical tags refspec
+		 */
 		if (tags == TAGS_SET) {
 			const char *tags_str = "refs/tags/*:refs/tags/*";
 			struct refspec *tags_refspec, *refspec;
@@ -848,7 +864,7 @@ static void add_options_to_argv(struct argv_array *argv)
 {
 	if (dry_run)
 		argv_array_push(argv, "--dry-run");
-	if (prune)
+	if (prune > 0)
 		argv_array_push(argv, "--prune");
 	if (update_head_ok)
 		argv_array_push(argv, "--update-head-ok");
@@ -916,6 +932,17 @@ static int fetch_one(struct remote *remote, int argc, const char **argv)
 		    "remote name from which new revisions should be fetched."));
 
 	transport = transport_get(remote, NULL);
+
+	if (prune < 0) {
+		/* no command line request */
+		if (0 <= transport->remote->prune)
+			prune = transport->remote->prune;
+		else if (0 <= fetch_prune_config)
+			prune = fetch_prune_config;
+		else
+			prune = PRUNE_BY_DEFAULT;
+	}
+
 	transport_set_verbosity(transport, verbosity, progress);
 	if (upload_pack)
 		set_option(TRANS_OPT_UPLOADPACK, upload_pack);
@@ -973,6 +1000,8 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	for (i = 1; i < argc; i++)
 		strbuf_addf(&default_rla, " %s", argv[i]);
 
+	git_config(git_fetch_config, NULL);
+
 	argc = parse_options(argc, argv, prefix,
 			     builtin_fetch_options, builtin_fetch_usage, 0);