difftool: use "env_array" to simplify memory management

Amend code added in 03831ef7b50 (difftool: implement the functionality
in the builtin, 2017-01-19) to use the "env_array" in the
run_command.[ch] API. Now we no longer need to manage our own
"index_env" buffer.

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 4931c108451721ebd49a3009adb431dbe41eb662..4ee40fe3a0698d2cb1468c81f56062de49a82d5e 100644 (file)
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -202,15 +202,10 @@ static void changed_files(struct hashmap *result, const char *index_path,
 {
        struct child_process update_index = CHILD_PROCESS_INIT;
        struct child_process diff_files = CHILD_PROCESS_INIT;
-       struct strbuf index_env = STRBUF_INIT, buf = STRBUF_INIT;
-       const char *git_dir = absolute_path(get_git_dir()), *env[] = {
-               NULL, NULL
-       };
+       struct strbuf buf = STRBUF_INIT;
+       const char *git_dir = absolute_path(get_git_dir());
        FILE *fp;
 
-       strbuf_addf(&index_env, "GIT_INDEX_FILE=%s", index_path);
-       env[0] = index_env.buf;
-
        strvec_pushl(&update_index.args,
                     "--git-dir", git_dir, "--work-tree", workdir,
                     "update-index", "--really-refresh", "-q",
@@ -222,7 +217,7 @@ static void changed_files(struct hashmap *result, const char *index_path,
        update_index.use_shell = 0;
        update_index.clean_on_exit = 1;
        update_index.dir = workdir;
-       update_index.env = env;
+       strvec_pushf(&update_index.env_array, "GIT_INDEX_FILE=%s", index_path);
        /* Ignore any errors of update-index */
        run_command(&update_index);
 
@@ -235,7 +230,7 @@ static void changed_files(struct hashmap *result, const char *index_path,
        diff_files.clean_on_exit = 1;
        diff_files.out = -1;
        diff_files.dir = workdir;
-       diff_files.env = env;
+       strvec_pushf(&diff_files.env_array, "GIT_INDEX_FILE=%s", index_path);
        if (start_command(&diff_files))
                die("could not obtain raw diff");
        fp = xfdopen(diff_files.out, "r");
@@ -248,7 +243,6 @@ static void changed_files(struct hashmap *result, const char *index_path,
        fclose(fp);
        if (finish_command(&diff_files))
                die("diff-files did not exit properly");
-       strbuf_release(&index_env);
        strbuf_release(&buf);
 }