Merge branch 'ws/fast-export-with-revision-options'

Use of certain "git rev-list" options with "git fast-export"
created nonsense results (the worst two of which being "--reverse"
and "--invert-grep --grep=<foo>").  The use of "--first-parent" is
made to behave a bit more sensible than before.

* ws/fast-export-with-revision-options:
  fast-export: fix surprising behavior with --first-parent

Author: gitster

builtin/fast-export.c

@@ -107,18 +107,6 @@ static int parse_opt_reencode_mode(const struct option *opt,
 
 static struct decoration idnums;
 static uint32_t last_idnum;
-
-static int has_unshown_parent(struct commit *commit)
-{
-	struct commit_list *parent;
-
-	for (parent = commit->parents; parent; parent = parent->next)
-		if (!(parent->item->object.flags & SHOWN) &&
-		    !(parent->item->object.flags & UNINTERESTING))
-			return 1;
-	return 0;
-}
-
 struct anonymized_entry {
 	struct hashmap_entry hash;
 	const char *anon;
@@ -752,20 +740,6 @@ static char *anonymize_tag(void *data)
 	return strbuf_detach(&out, NULL);
 }
 
-static void handle_tail(struct object_array *commits, struct rev_info *revs,
-			struct string_list *paths_of_changed_objects)
-{
-	struct commit *commit;
-	while (commits->nr) {
-		commit = (struct commit *)object_array_pop(commits);
-		if (has_unshown_parent(commit)) {
-			/* Queue again, to be handled later */
-			add_object_array(&commit->object, NULL, commits);
-			return;
-		}
-		handle_commit(commit, revs, paths_of_changed_objects);
-	}
-}
 
 static void handle_tag(const char *name, struct tag *tag)
 {
@@ -1185,7 +1159,6 @@ static int parse_opt_anonymize_map(const struct option *opt,
 int cmd_fast_export(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
-	struct object_array commits = OBJECT_ARRAY_INIT;
 	struct commit *commit;
 	char *export_filename = NULL,
 	     *import_filename = NULL,
@@ -1283,18 +1256,13 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
 
 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");
+
+	revs.reverse = 1;
 	revs.diffopt.format_callback = show_filemodify;
 	revs.diffopt.format_callback_data = &paths_of_changed_objects;
 	revs.diffopt.flags.recursive = 1;
-	while ((commit = get_revision(&revs))) {
-		if (has_unshown_parent(commit)) {
-			add_object_array(&commit->object, NULL, &commits);
-		}
-		else {
-			handle_commit(commit, &revs, &paths_of_changed_objects);
-			handle_tail(&commits, &revs, &paths_of_changed_objects);
-		}
-	}
+	while ((commit = get_revision(&revs)))
+		handle_commit(commit, &revs, &paths_of_changed_objects);
 
 	handle_tags_and_duplicates(&extra_refs);
 	handle_tags_and_duplicates(&tag_refs);

t/t9350-fast-export.sh

@@ -750,4 +750,36 @@ test_expect_success 'merge commit gets exported with --import-marks' '
 	)
 '
 
+
+test_expect_success 'fast-export --first-parent outputs all revisions output by revision walk' '
+	git init first-parent &&
+	(
+		cd first-parent &&
+		test_commit A &&
+		git checkout -b topic1 &&
+		test_commit B &&
+		git checkout main &&
+		git merge --no-ff topic1 &&
+
+		git checkout -b topic2 &&
+		test_commit C &&
+		git checkout main &&
+		git merge --no-ff topic2 &&
+
+		test_commit D &&
+
+		git fast-export main -- --first-parent >first-parent-export &&
+		git fast-export main -- --first-parent --reverse >first-parent-reverse-export &&
+		test_cmp first-parent-export first-parent-reverse-export &&
+
+		git init import &&
+		git -C import fast-import <first-parent-export &&
+
+		git log --format="%ad %s" --first-parent main >expected &&
+		git -C import log --format="%ad %s" --all >actual &&
+		test_cmp expected actual &&
+		test_line_count = 4 actual
+	)
+'
+
 test_done