4 files changed, 52 insertions, 0 deletions

diff --git a/submodule-config.c b/submodule-config.c
index afe0ea815..a5cd2ee77 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -59,6 +59,7 @@ static void free_one_config(struct submodule_entry *entry)
 {
 	free((void *) entry->config->path);
 	free((void *) entry->config->name);
+	free((void *) entry->config->update_strategy.command);
 	free(entry->config);
 }
 
@@ -194,6 +195,8 @@ static struct submodule *lookup_or_create_by_name(struct submodule_cache *cache,
 
 	submodule->path = NULL;
 	submodule->url = NULL;
+	submodule->update_strategy.type = SM_UPDATE_UNSPECIFIED;
+	submodule->update_strategy.command = NULL;
 	submodule->fetch_recurse = RECURSE_SUBMODULES_NONE;
 	submodule->ignore = NULL;
 
@@ -311,6 +314,16 @@ static int parse_config(const char *var, const char *value, void *data)
 			free((void *) submodule->url);
 			submodule->url = xstrdup(value);
 		}
+	} else if (!strcmp(item.buf, "update")) {
+		if (!value)
+			ret = config_error_nonbool(var);
+		else if (!me->overwrite &&
+			 submodule->update_strategy.type != SM_UPDATE_UNSPECIFIED)
+			warn_multiple_config(me->commit_sha1, submodule->name,
+					     "update");
+		else if (parse_submodule_update_strategy(value,
+			 &submodule->update_strategy) < 0)
+				die(_("invalid value for %s"), var);
 	}
 
 	strbuf_release(&name);
diff --git a/submodule-config.h b/submodule-config.h
index 9061e4ed3..092ebfc93 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -2,6 +2,7 @@
 #define SUBMODULE_CONFIG_CACHE_H
 
 #include "hashmap.h"
+#include "submodule.h"
 #include "strbuf.h"
 
 /*
@@ -14,6 +15,7 @@ struct submodule {
 	const char *url;
 	int fetch_recurse;
 	const char *ignore;
+	struct submodule_update_strategy update_strategy;
 	/* the sha1 blob id of the responsible .gitmodules file */
 	unsigned char gitmodules_sha1[20];
 };
diff --git a/submodule.c b/submodule.c
index 916fc84aa..c3a1300a5 100644
--- a/submodule.c
+++ b/submodule.c
@@ -210,6 +210,27 @@ void gitmodules_config(void)
 	}
 }
 
+int parse_submodule_update_strategy(const char *value,
+		struct submodule_update_strategy *dst)
+{
+	free((void*)dst->command);
+	dst->command = NULL;
+	if (!strcmp(value, "none"))
+		dst->type = SM_UPDATE_NONE;
+	else if (!strcmp(value, "checkout"))
+		dst->type = SM_UPDATE_CHECKOUT;
+	else if (!strcmp(value, "rebase"))
+		dst->type = SM_UPDATE_REBASE;
+	else if (!strcmp(value, "merge"))
+		dst->type = SM_UPDATE_MERGE;
+	else if (skip_prefix(value, "!", &value)) {
+		dst->type = SM_UPDATE_COMMAND;
+		dst->command = xstrdup(value);
+	} else
+		return -1;
+	return 0;
+}
+
 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 				  const char *arg)
 {
diff --git a/submodule.h b/submodule.h
index cbc000304..346450062 100644
--- a/submodule.h
+++ b/submodule.h
@@ -13,6 +13,20 @@ enum {
 	RECURSE_SUBMODULES_ON = 2
 };
 
+enum submodule_update_type {
+	SM_UPDATE_UNSPECIFIED = 0,
+	SM_UPDATE_CHECKOUT,
+	SM_UPDATE_REBASE,
+	SM_UPDATE_MERGE,
+	SM_UPDATE_NONE,
+	SM_UPDATE_COMMAND
+};
+
+struct submodule_update_strategy {
+	enum submodule_update_type type;
+	const char *command;
+};
+
 int is_staging_gitmodules_ok(void);
 int update_path_in_gitmodules(const char *oldpath, const char *newpath);
 int remove_path_from_gitmodules(const char *path);
@@ -21,6 +35,8 @@ void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 		const char *path);
 int submodule_config(const char *var, const char *value, void *cb);
 void gitmodules_config(void);
+int parse_submodule_update_strategy(const char *value,
+		struct submodule_update_strategy *dst);
 void handle_ignore_submodules_arg(struct diff_options *diffopt, const char *);
 void show_submodule_summary(FILE *f, const char *path,
 		const char *line_prefix,