[PATCH v2 1/2] rm: better error message on failure for multiple files

[Mathieu Lienard--Mayor <Mathieu.Lienard--Mayor@ensimag.imag.fr>]

When 'git rm' fails, it now displays a single message
with the list of files involved, instead of displaying
a list of messages with one file each.

As an example, the old message:
	error: 'foo.txt' has changes staged in the index
	(use --cached to keep the file, or -f to force removal)
	error: 'bar.txt' has changes staged in the index
	(use --cached to keep the file, or -f to force removal)

would now be displayed as:
	error: the following files have changes staged in the index:
	    foo.txt
	    bar.txt
	(use --cached to keep the file, or -f to force removal)

Signed-off-by: Mathieu Lienard--Mayor <Mathieu.Lienard--Mayor@ensimag.imag.fr>
Signed-off-by: Jorge Juan Garcia Garcia <Jorge-Juan.Garcia-Garcia@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
---

Changes since v1:
 -introduction of print_error_files() to avoid repetitions
 -implementation with string_list instead of strbuf 
 -typo "fileand" switched to "file and"

 builtin/rm.c  |   74 ++++++++++++++++++++++++++++++++++++++++++++++----------
 t/t3600-rm.sh |   48 +++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+), 14 deletions(-)

diff --git a/builtin/rm.c b/builtin/rm.c
index 7b91d52..76dfc5b 100644
--- a/builtin/rm.c
+++ b/builtin/rm.c
@@ -70,6 +70,27 @@ static int check_submodules_use_gitfiles(void)
 	return errs;
 }
 
+/*
+ * PRECONDITION: files_list is a non-empty string_list
+ */
+static int print_error_files(struct string_list *files_list,
+			     const char *main_msg,
+			     const char *hints_msg)
+{
+	int errs = 0;
+	struct strbuf err_msg = STRBUF_INIT;
+	int i;
+	strbuf_addstr(&err_msg, main_msg);
+	for (i = 0; i < files_list->nr; i++)
+		strbuf_addf(&err_msg,
+			    "\n    %s",
+			    files_list->items[i].string);
+	strbuf_addstr(&err_msg, hints_msg);
+	errs = error("%s", err_msg.buf);
+
+	return errs;
+}
+
 static int check_local_mod(unsigned char *head, int index_only)
 {
 	/*
@@ -82,6 +103,11 @@ static int check_local_mod(unsigned char *head, int index_only)
 	int i, no_head;
 	int errs = 0;
 
+	struct string_list files_staged = STRING_LIST_INIT_NODUP;
+	struct string_list files_cached = STRING_LIST_INIT_NODUP;
+	struct string_list files_submodule = STRING_LIST_INIT_NODUP;
+	struct string_list files_local = STRING_LIST_INIT_NODUP;
+
 	no_head = is_null_sha1(head);
 	for (i = 0; i < list.nr; i++) {
 		struct stat st;
@@ -171,29 +197,49 @@ static int check_local_mod(unsigned char *head, int index_only)
 		 */
 		if (local_changes && staged_changes) {
 			if (!index_only || !(ce->ce_flags & CE_INTENT_TO_ADD))
-				errs = error(_("'%s' has staged content different "
-					     "from both the file and the HEAD\n"
-					     "(use -f to force removal)"), name);
+				string_list_append(&files_staged, name);
 		}
 		else if (!index_only) {
 			if (staged_changes)
-				errs = error(_("'%s' has changes staged in the index\n"
-					     "(use --cached to keep the file, "
-					     "or -f to force removal)"), name);
+				string_list_append(&files_cached, name);
 			if (local_changes) {
 				if (S_ISGITLINK(ce->ce_mode) &&
 				    !submodule_uses_gitfile(name)) {
-					errs = error(_("submodule '%s' (or one of its nested "
-						     "submodules) uses a .git directory\n"
-						     "(use 'rm -rf' if you really want to remove "
-						     "it including all of its history)"), name);
-				} else
-					errs = error(_("'%s' has local modifications\n"
-						     "(use --cached to keep the file, "
-						     "or -f to force removal)"), name);
+					string_list_append(&files_submodule,
+							   name);
+				} else {
+					string_list_append(&files_local, name);
+				}
 			}
 		}
 	}
+	if (files_staged.nr)
+		errs = print_error_files(&files_staged,
+					 _("the following files have staged "
+					   "content different from both the"
+					   "\nfile and the HEAD:"),
+					 _("\n(use -f to force removal)"));
+	if (files_cached.nr)
+		errs = print_error_files(&files_cached,
+					 _("the following files have changes "
+					   "staged in the index:"),
+					 _("\n(use --cached to keep the file, "
+					   "or -f to force removal)"));
+	if (files_submodule.nr)
+		errs = print_error_files(&files_submodule,
+					 _("the following submodules (or one "
+					   "of its nested submodule) use a "
+					   ".git directory:"),
+					 _("\n(use 'rm -rf' if you really "
+					   "want to remove i including all "
+					   "of its history)"));
+	if (files_local.nr)
+		errs = print_error_files(&files_local,
+					 _("the following files have "
+					   "local modifications:"),
+					 _("\n(use --cached to keep the file, "
+					   "or -f to force removal)"));
+
 	return errs;
 }
 
diff --git a/t/t3600-rm.sh b/t/t3600-rm.sh
index 0c44e9f..08bc9bb 100755
--- a/t/t3600-rm.sh
+++ b/t/t3600-rm.sh
@@ -687,4 +687,52 @@ test_expect_failure SYMLINKS 'rm across a symlinked leading path (w/ index)' '
 	test_path_is_file e/f
 '
 
+test_expect_success 'setup for testing rm messages' '
+	>bar.txt &&
+	>foo.txt &&
+	git add bar.txt foo.txt
+'
+
+test_expect_success 'rm files with different staged content' '
+	cat >expect << EOF &&
+error: the following files have staged content different from both the
+file and the HEAD:
+    bar.txt
+    foo.txt
+(use -f to force removal)
+EOF
+	echo content1 >foo.txt &&
+	echo content1 >bar.txt &&
+	test_must_fail git rm foo.txt bar.txt 2>actual &&
+	test_cmp expect actual
+'
+
+
+test_expect_success 'rm file with local modification' '
+	cat >expect << EOF &&
+error: the following files have local modifications:
+    foo.txt
+(use --cached to keep the file, or -f to force removal)
+EOF
+	git commit -m "testing rm 3" &&
+	echo content3 >foo.txt &&
+	test_must_fail git rm foo.txt 2>actual &&
+	test_cmp expect actual
+'
+
+
+test_expect_success 'rm file with changes in the index' '
+    cat >expect << EOF &&
+error: the following files have changes staged in the index:
+    foo.txt
+(use --cached to keep the file, or -f to force removal)
+EOF
+	git reset --hard &&
+	echo content5 >foo.txt &&
+	git add foo.txt &&
+	test_must_fail git rm foo.txt 2>actual &&
+	test_cmp expect actual
+'
+
+
 test_done
-- 
1.7.8