Merge branch 'cc/interpret-trailers-more'

"git interpret-trailers" learned to properly handle the
"Conflicts:" block at the end.

* cc/interpret-trailers-more:
  trailer: add test with an old style conflict block
  trailer: reuse ignore_non_trailer() to ignore conflict lines
  commit: make ignore_non_trailer() non static
  merge & sequencer: turn "Conflicts:" hint into a comment
  builtin/commit.c: extract ignore_non_trailer() helper function
  merge & sequencer: unify codepaths that write "Conflicts:" hint
  builtin/merge.c: drop a parameter that is never used

9 files changed, 170 insertions, 72 deletions

diff --git a/builtin/commit.c b/builtin/commit.c
index e108c53015..cda74e9a68 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -800,32 +800,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	if (clean_message_contents)
 		stripspace(&sb, 0);
 
-	if (signoff) {
-		/*
-		 * See if we have a Conflicts: block at the end. If yes, count
-		 * its size, so we can ignore it.
-		 */
-		int ignore_footer = 0;
-		int i, eol, previous = 0;
-		const char *nl;
-
-		for (i = 0; i < sb.len; i++) {
-			nl = memchr(sb.buf + i, '\n', sb.len - i);
-			if (nl)
-				eol = nl - sb.buf;
-			else
-				eol = sb.len;
-			if (starts_with(sb.buf + previous, "\nConflicts:\n")) {
-				ignore_footer = sb.len - previous;
-				break;
-			}
-			while (i < eol)
-				i++;
-			previous = eol;
-		}
-
-		append_signoff(&sb, ignore_footer, 0);
-	}
+	if (signoff)
+		append_signoff(&sb, ignore_non_trailer(&sb), 0);
 
 	if (fwrite(sb.buf, 1, sb.len, s->fp) < sb.len)
 		die_errno(_("could not write commit template"));
diff --git a/builtin/merge.c b/builtin/merge.c
index bebbe5b308..215d4856e5 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -29,6 +29,7 @@
 #include "remote.h"
 #include "fmt-merge-msg.h"
 #include "gpg-interface.h"
+#include "sequencer.h"
 
 #define DEFAULT_TWOHEAD (1<<0)
 #define DEFAULT_OCTOPUS (1<<1)
@@ -880,28 +881,19 @@ static int finish_automerge(struct commit *head,
 	return 0;
 }
 
-static int suggest_conflicts(int renormalizing)
+static int suggest_conflicts(void)
 {
 	const char *filename;
 	FILE *fp;
-	int pos;
+	struct strbuf msgbuf = STRBUF_INIT;
 
 	filename = git_path("MERGE_MSG");
 	fp = fopen(filename, "a");
 	if (!fp)
 		die_errno(_("Could not open '%s' for writing"), filename);
-	fprintf(fp, "\nConflicts:\n");
-	for (pos = 0; pos < active_nr; pos++) {
-		const struct cache_entry *ce = active_cache[pos];
-
-		if (ce_stage(ce)) {
-			fprintf(fp, "\t%s\n", ce->name);
-			while (pos + 1 < active_nr &&
-					!strcmp(ce->name,
-						active_cache[pos + 1]->name))
-				pos++;
-		}
-	}
+
+	append_conflicts_hint(&msgbuf);
+	fputs(msgbuf.buf, fp);
 	fclose(fp);
 	rerere(allow_rerere_auto);
 	printf(_("Automatic merge failed; "
@@ -1550,7 +1542,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		fprintf(stderr, _("Automatic merge went well; "
 			"stopped before committing as requested\n"));
 	else
-		ret = suggest_conflicts(option_renormalize);
+		ret = suggest_conflicts();
 
 done:
 	free(branch_to_free);
diff --git a/commit.c b/commit.c
index 19cf8f9c67..a54cb9a454 100644
--- a/commit.c
+++ b/commit.c
@@ -1640,3 +1640,49 @@ const char *find_commit_header(const char *msg, const char *key, size_t *out_len
 	}
 	return NULL;
 }
+
+/*
+ * Inspect sb and determine the true "end" of the log message, in
+ * order to find where to put a new Signed-off-by: line.  Ignored are
+ * trailing comment lines and blank lines, and also the traditional
+ * "Conflicts:" block that is not commented out, so that we can use
+ * "git commit -s --amend" on an existing commit that forgot to remove
+ * it.
+ *
+ * Returns the number of bytes from the tail to ignore, to be fed as
+ * the second parameter to append_signoff().
+ */
+int ignore_non_trailer(struct strbuf *sb)
+{
+	int boc = 0;
+	int bol = 0;
+	int in_old_conflicts_block = 0;
+
+	while (bol < sb->len) {
+		char *next_line;
+
+		if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
+			next_line = sb->buf + sb->len;
+		else
+			next_line++;
+
+		if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
+			/* is this the first of the run of comments? */
+			if (!boc)
+				boc = bol;
+			/* otherwise, it is just continuing */
+		} else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
+			in_old_conflicts_block = 1;
+			if (!boc)
+				boc = bol;
+		} else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
+			; /* a pathname in the conflicts block */
+		} else if (boc) {
+			/* the previous was not trailing comment */
+			boc = 0;
+			in_old_conflicts_block = 0;
+		}
+		bol = next_line - sb->buf;
+	}
+	return boc ? sb->len - boc : 0;
+}
diff --git a/commit.h b/commit.h
index bc68ccbe69..cd35ac150a 100644
--- a/commit.h
+++ b/commit.h
@@ -337,6 +337,9 @@ extern void free_commit_extra_headers(struct commit_extra_header *extra);
 extern const char *find_commit_header(const char *msg, const char *key,
 				      size_t *out_len);
 
+/* Find the end of the log message, the right place for a new trailer. */
+extern int ignore_non_trailer(struct strbuf *sb);
+
 typedef void (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
 				 void *cb_data);
 
diff --git a/sequencer.c b/sequencer.c
index a03d4fa252..77a1266760 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -267,6 +267,23 @@ static int fast_forward_to(const unsigned char *to, const unsigned char *from,
 	return 0;
 }
 
+void append_conflicts_hint(struct strbuf *msgbuf)
+{
+	int i;
+
+	strbuf_addch(msgbuf, '\n');
+	strbuf_commented_addf(msgbuf, "Conflicts:\n");
+	for (i = 0; i < active_nr;) {
+		const struct cache_entry *ce = active_cache[i++];
+		if (ce_stage(ce)) {
+			strbuf_commented_addf(msgbuf, "\t%s\n", ce->name);
+			while (i < active_nr && !strcmp(ce->name,
+							active_cache[i]->name))
+				i++;
+		}
+	}
+}
+
 static int do_recursive_merge(struct commit *base, struct commit *next,
 			      const char *base_label, const char *next_label,
 			      unsigned char *head, struct strbuf *msgbuf,
@@ -307,21 +324,8 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
 	if (opts->signoff)
 		append_signoff(msgbuf, 0, 0);
 
-	if (!clean) {
-		int i;
-		strbuf_addstr(msgbuf, "\nConflicts:\n");
-		for (i = 0; i < active_nr;) {
-			const struct cache_entry *ce = active_cache[i++];
-			if (ce_stage(ce)) {
-				strbuf_addch(msgbuf, '\t');
-				strbuf_addstr(msgbuf, ce->name);
-				strbuf_addch(msgbuf, '\n');
-				while (i < active_nr && !strcmp(ce->name,
-						active_cache[i]->name))
-					i++;
-			}
-		}
-	}
+	if (!clean)
+		append_conflicts_hint(msgbuf);
 
 	return !clean;
 }
diff --git a/sequencer.h b/sequencer.h
index db43e9cf86..5ed5cb1d97 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -53,5 +53,6 @@ int sequencer_pick_revisions(struct replay_opts *opts);
 extern const char sign_off_header[];
 
 void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag);
+void append_conflicts_hint(struct strbuf *msgbuf);
 
 #endif
diff --git a/t/t3507-cherry-pick-conflict.sh b/t/t3507-cherry-pick-conflict.sh
index 223b98433c..7c5ad08626 100755
--- a/t/t3507-cherry-pick-conflict.sh
+++ b/t/t3507-cherry-pick-conflict.sh
@@ -351,19 +351,45 @@ test_expect_success 'commit after failed cherry-pick does not add duplicated -s'
 test_expect_success 'commit after failed cherry-pick adds -s at the right place' '
 	pristine_detach initial &&
 	test_must_fail git cherry-pick picked &&
+
 	git commit -a -s &&
-	pwd &&
-	cat <<EOF > expected &&
-picked
 
-Signed-off-by: C O Mitter <committer@example.com>
+	# Do S-o-b and Conflicts appear in the right order?
+	cat <<-\EOF >expect &&
+	Signed-off-by: C O Mitter <committer@example.com>
+	# Conflicts:
+	EOF
+	grep -e "^# Conflicts:" -e '^Signed-off-by' <.git/COMMIT_EDITMSG >actual &&
+	test_cmp expect actual &&
+
+	cat <<-\EOF >expected &&
+	picked
 
-Conflicts:
-	foo
-EOF
+	Signed-off-by: C O Mitter <committer@example.com>
+	EOF
 
-	git show -s --pretty=format:%B > actual &&
+	git show -s --pretty=format:%B >actual &&
 	test_cmp expected actual
 '
 
+test_expect_success 'commit --amend -s places the sign-off at the right place' '
+	pristine_detach initial &&
+	test_must_fail git cherry-pick picked &&
+
+	# emulate old-style conflicts block
+	mv .git/MERGE_MSG .git/MERGE_MSG+ &&
+	sed -e "/^# Conflicts:/,\$s/^# *//" <.git/MERGE_MSG+ >.git/MERGE_MSG &&
+
+	git commit -a &&
+	git commit --amend -s &&
+
+	# Do S-o-b and Conflicts appear in the right order?
+	cat <<-\EOF >expect &&
+	Signed-off-by: C O Mitter <committer@example.com>
+	Conflicts:
+	EOF
+	grep -e "^Conflicts:" -e '^Signed-off-by' <.git/COMMIT_EDITMSG >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index 1efb88051a..bd0ab46750 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -213,7 +213,7 @@ test_expect_success 'with 2 files arguments' '
 '
 
 test_expect_success 'with message that has comments' '
-	cat basic_message >>message_with_comments &&
+	cat basic_message >message_with_comments &&
 	sed -e "s/ Z\$/ /" >>message_with_comments <<-\EOF &&
 		# comment
 
@@ -232,12 +232,44 @@ test_expect_success 'with message that has comments' '
 
 		Reviewed-by: Johan
 		Cc: Peff
+		# last comment
+
 	EOF
 	cat basic_patch >>expected &&
 	git interpret-trailers --trim-empty --trailer "Cc: Peff" message_with_comments >actual &&
 	test_cmp expected actual
 '
 
+test_expect_success 'with message that has an old style conflict block' '
+	cat basic_message >message_with_comments &&
+	sed -e "s/ Z\$/ /" >>message_with_comments <<-\EOF &&
+		# comment
+
+		# other comment
+		Cc: Z
+		# yet another comment
+		Reviewed-by: Johan
+		Reviewed-by: Z
+		# last comment
+
+		Conflicts:
+
+	EOF
+	cat basic_message >expected &&
+	cat >>expected <<-\EOF &&
+		# comment
+
+		Reviewed-by: Johan
+		Cc: Peff
+		# last comment
+
+		Conflicts:
+
+	EOF
+	git interpret-trailers --trim-empty --trailer "Cc: Peff" message_with_comments >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'with commit complex message and trailer args' '
 	cat complex_message_body >expected &&
 	sed -e "s/ Z\$/ /" >>expected <<-\EOF &&
diff --git a/trailer.c b/trailer.c
index a905f5c50c..623adeb02d 100644
--- a/trailer.c
+++ b/trailer.c
@@ -2,6 +2,7 @@
 #include "string-list.h"
 #include "run-command.h"
 #include "string-list.h"
+#include "commit.h"
 #include "trailer.h"
 /*
  * Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>
@@ -768,6 +769,22 @@ static int find_trailer_start(struct strbuf **lines, int count)
 	return only_spaces ? count : 0;
 }
 
+/* Get the index of the end of the trailers */
+static int find_trailer_end(struct strbuf **lines, int patch_start)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int i, ignore_bytes;
+
+	for (i = 0; i < patch_start; i++)
+		strbuf_addbuf(&sb, lines[i]);
+	ignore_bytes = ignore_non_trailer(&sb);
+	strbuf_release(&sb);
+	for (i = patch_start - 1; i >= 0 && ignore_bytes > 0; i--)
+		ignore_bytes -= lines[i]->len;
+
+	return i + 1;
+}
+
 static int has_blank_line_before(struct strbuf **lines, int start)
 {
 	for (;start >= 0; start--) {
@@ -790,14 +807,15 @@ static int process_input_file(struct strbuf **lines,
 			      struct trailer_item **in_tok_last)
 {
 	int count = 0;
-	int patch_start, trailer_start, i;
+	int patch_start, trailer_start, trailer_end, i;
 
 	/* Get the line count */
 	while (lines[count])
 		count++;
 
 	patch_start = find_patch_start(lines, count);
-	trailer_start = find_trailer_start(lines, patch_start);
+	trailer_end = find_trailer_end(lines, patch_start);
+	trailer_start = find_trailer_start(lines, trailer_end);
 
 	/* Print lines before the trailers as is */
 	print_lines(lines, 0, trailer_start);
@@ -806,14 +824,14 @@ static int process_input_file(struct strbuf **lines,
 		printf("\n");
 
 	/* Parse trailer lines */
-	for (i = trailer_start; i < patch_start; i++) {
+	for (i = trailer_start; i < trailer_end; i++) {
 		if (lines[i]->buf[0] != comment_line_char) {
 			struct trailer_item *new = create_trailer_item(lines[i]->buf);
 			add_trailer_item(in_tok_first, in_tok_last, new);
 		}
 	}
 
-	return patch_start;
+	return trailer_end;
 }
 
 static void free_all(struct trailer_item **first)
@@ -830,7 +848,7 @@ void process_trailers(const char *file, int trim_empty, struct string_list *trai
 	struct trailer_item *in_tok_last = NULL;
 	struct trailer_item *arg_tok_first;
 	struct strbuf **lines;
-	int patch_start;
+	int trailer_end;
 
 	/* Default config must be setup first */
 	git_config(git_trailer_default_config, NULL);
@@ -839,7 +857,7 @@ void process_trailers(const char *file, int trim_empty, struct string_list *trai
 	lines = read_input_file(file);
 
 	/* Print the lines before the trailers */
-	patch_start = process_input_file(lines, &in_tok_first, &in_tok_last);
+	trailer_end = process_input_file(lines, &in_tok_first, &in_tok_last);
 
 	arg_tok_first = process_command_line_args(trailers);
 
@@ -850,7 +868,7 @@ void process_trailers(const char *file, int trim_empty, struct string_list *trai
 	free_all(&in_tok_first);
 
 	/* Print the lines after the trailers as is */
-	print_lines(lines, patch_start, INT_MAX);
+	print_lines(lines, trailer_end, INT_MAX);
 
 	strbuf_list_free(lines);
 }