difftool: prepare "struct child_process" in cmd_difftool()

Move the preparation of the "struct child_process" from run_dir_diff()
to its only caller, cmd_difftool(). This is in preparation for
migrating run_file_diff() to using the run_command() API directly, and
to move more of the shared setup of the two to cmd_difftool().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/difftool.c b/builtin/difftool.c
index 6a9242a80329559eda808b169b4522cae7f95469..9f08a8f3fd2de673dcc14f9d972be7cf655ad08e 100644 (file)
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -331,7 +331,8 @@ static int checkout_path(unsigned mode, struct object_id *oid,
 }
 
 static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
-                       int argc, const char **argv)
+                       int argc, const char **argv,
+                       struct child_process *child)
 {
        char tmpdir[PATH_MAX];
        struct strbuf info = STRBUF_INIT, lpath = STRBUF_INIT;
@@ -352,7 +353,6 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        struct index_state wtindex;
        struct checkout lstate, rstate;
        int rc, flags = RUN_GIT_CMD, err = 0;
-       struct child_process child = CHILD_PROCESS_INIT;
        const char *helper_argv[] = { "difftool--helper", NULL, NULL, NULL };
        struct hashmap wt_modified, tmp_modified;
        int indices_loaded = 0;
@@ -387,19 +387,19 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        rdir_len = rdir.len;
        wtdir_len = wtdir.len;
 
-       child.no_stdin = 1;
-       child.git_cmd = 1;
-       child.use_shell = 0;
-       child.clean_on_exit = 1;
-       child.dir = prefix;
-       child.out = -1;
-       strvec_pushl(&child.args, "diff", "--raw", "--no-abbrev", "-z",
+       child->no_stdin = 1;
+       child->git_cmd = 1;
+       child->use_shell = 0;
+       child->clean_on_exit = 1;
+       child->dir = prefix;
+       child->out = -1;
+       strvec_pushl(&child->args, "diff", "--raw", "--no-abbrev", "-z",
                     NULL);
        for (i = 0; i < argc; i++)
-               strvec_push(&child.args, argv[i]);
-       if (start_command(&child))
+               strvec_push(&child->args, argv[i]);
+       if (start_command(child))
                die("could not obtain raw diff");
-       fp = xfdopen(child.out, "r");
+       fp = xfdopen(child->out, "r");
 
        /* Build index info for left and right sides of the diff */
        i = 0;
@@ -525,7 +525,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 
        fclose(fp);
        fp = NULL;
-       if (finish_command(&child)) {
+       if (finish_command(child)) {
                ret = error("error occurred running diff --raw");
                goto finish;
        }
@@ -719,6 +719,7 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
                OPT_ARGUMENT("no-index", &no_index, N_("passed to `diff`")),
                OPT_END()
        };
+       struct child_process child = CHILD_PROCESS_INIT;
 
        git_config(difftool_config, NULL);
        symlinks = has_symlinks;
@@ -769,6 +770,6 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
         * each file that changed.
         */
        if (dir_diff)
-               return run_dir_diff(extcmd, symlinks, prefix, argc, argv);
+               return run_dir_diff(extcmd, symlinks, prefix, argc, argv, &child);
        return run_file_diff(prompt, prefix, argc, argv);
 }