pull: implement fetch + merge

Implement the fetch + merge functionality of git-pull, by first running
git-fetch with the repo and refspecs provided on the command line, then
running git-merge on FETCH_HEAD to merge the fetched refs into the
current branch.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/pull.c b/builtin/pull.c
index cabeed4530d68625e086c79597465b27fd0d7a98..91575361be66257b33bdaae86c429c047d652533 100644 (file)
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -9,8 +9,10 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "exec_cmd.h"
 #include "builtin.h"
 #include "parse-options.h"
 #include "exec_cmd.h"

+#include "run-command.h"

 
 static const char * const pull_usage[] = {
 
 static const char * const pull_usage[] = {

+       N_("git pull [options] [<repository> [<refspec>...]]"),

        NULL
 };
 
        NULL
 };
 


@@ -18,8 +20,61 @@ static struct option pull_options[] = {
        OPT_END()
 };
 
        OPT_END()
 };
 

+/**
+ * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
+ * as a string and `refspecs` as a null-terminated array of strings. If `repo`
+ * is not provided in argv, it is set to NULL.
+ */
+static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
+               const char ***refspecs)
+{
+       if (argc > 0) {
+               *repo = *argv++;
+               argc--;
+       } else
+               *repo = NULL;
+       *refspecs = argv;
+}
+
+/**
+ * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
+ * repository and refspecs to fetch, or NULL if they are not provided.
+ */
+static int run_fetch(const char *repo, const char **refspecs)
+{
+       struct argv_array args = ARGV_ARRAY_INIT;
+       int ret;
+
+       argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
+       if (repo) {
+               argv_array_push(&args, repo);
+               argv_array_pushv(&args, refspecs);
+       } else if (*refspecs)
+               die("BUG: refspecs without repo?");
+       ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
+       argv_array_clear(&args);
+       return ret;
+}
+
+/**
+ * Runs git-merge, returning its exit status.
+ */
+static int run_merge(void)
+{
+       int ret;
+       struct argv_array args = ARGV_ARRAY_INIT;
+
+       argv_array_pushl(&args, "merge", NULL);
+       argv_array_push(&args, "FETCH_HEAD");
+       ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
+       argv_array_clear(&args);
+       return ret;
+}
+

 int cmd_pull(int argc, const char **argv, const char *prefix)
 {
 int cmd_pull(int argc, const char **argv, const char *prefix)
 {

+       const char *repo, **refspecs;
+

        if (!getenv("_GIT_USE_BUILTIN_PULL")) {
                const char *path = mkpath("%s/git-pull", git_exec_path());
 
        if (!getenv("_GIT_USE_BUILTIN_PULL")) {
                const char *path = mkpath("%s/git-pull", git_exec_path());
 


@@ -29,5 +84,10 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 
        argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
 
 
        argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
 

-       return 0;
+       parse_repo_refspecs(argc, argv, &repo, &refspecs);
+
+       if (run_fetch(repo, refspecs))
+               return 1;
+
+       return run_merge();

 }
 }