Pass command line args through to diff-files in status view (#1155)

This makes it possible to use `tig --ignore-submodules` to speed up
the status view for a repo with many submodules.

Closes #1152

Reported-by: Benjamin Titmus <ben.titmus@cantab.net>
Reviewed-by: Johannes Altmanninger <aclopte@gmail.com>

include/tig/git.h

@@ -36,10 +36,11 @@
 
 /* Don't show staged unmerged entries. */
 #define GIT_DIFF_STAGED_FILES(output_arg) \
-	"git", "diff-index", (output_arg), "--diff-filter=ACDMRTXB", "-C", "--cached", "HEAD", "--", NULL
+	"git", "diff-index", (output_arg), "%(cmdlineargs)", "--diff-filter=ACDMRTXB", \
+		"-C", "--cached", "HEAD", "--", NULL
 
 #define GIT_DIFF_UNSTAGED_FILES(output_arg) \
-	"git", "diff-files", (output_arg), NULL
+	"git", "diff-files", (output_arg), "%(cmdlineargs)", NULL
 
 #define GIT_DIFF_BLAME(encoding_arg, context_arg, space_arg, new_name) \
 	GIT_DIFF_UNSTAGED(encoding_arg, context_arg, space_arg, "", new_name)

src/status.c

@@ -90,8 +90,13 @@ status_run(struct view *view, const char *argv[], char status, enum line_type ty
 	struct status *unmerged = NULL;
 	struct buffer buf;
 	struct io io;
+	const char **status_argv = NULL;
+	bool ok = argv_format(view->env, &status_argv, argv, false, false) &&
+		  io_run(&io, IO_RD, repo.exec_dir, NULL, status_argv);
 
-	if (!io_run(&io, IO_RD, repo.exec_dir, NULL, argv))
+	argv_free(status_argv);
+	free(status_argv);
+	if (!ok)
 		return false;
 
 	add_line_nodata(view, type);