Merge branch 'maint'

* maint:
  Trailing whitespace and no newline fix
  diff --cc: a lost line at the beginning of the file is shown incorrectly
  combine-diff.c: fix performance problem when folding common deleted lines

4 files changed, 118 insertions, 18 deletions

diff --git a/combine-diff.c b/combine-diff.c
index bbf74fc42e..5b63af1eeb 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -80,6 +80,7 @@ struct lline {
 /* Lines surviving in the merge result */
 struct sline {
 	struct lline *lost_head, **lost_tail;
+	struct lline *next_lost;
 	char *bol;
 	int len;
 	/* bit 0 up to (N-1) are on if the parent has this line (i.e.
@@ -121,18 +122,12 @@ static void append_lost(struct sline *sline, int n, const char *line, int len)
 
 	/* Check to see if we can squash things */
 	if (sline->lost_head) {
-		struct lline *last_one = NULL;
-		/* We cannot squash it with earlier one */
-		for (lline = sline->lost_head;
-		     lline;
-		     lline = lline->next)
-			if (lline->parent_map & this_mask)
-				last_one = lline;
-		lline = last_one ? last_one->next : sline->lost_head;
+		lline = sline->next_lost;
 		while (lline) {
 			if (lline->len == len &&
 			    !memcmp(lline->line, line, len)) {
 				lline->parent_map |= this_mask;
+				sline->next_lost = lline->next;
 				return;
 			}
 			lline = lline->next;
@@ -147,6 +142,7 @@ static void append_lost(struct sline *sline, int n, const char *line, int len)
 	lline->line[len] = 0;
 	*sline->lost_tail = lline;
 	sline->lost_tail = &lline->next;
+	sline->next_lost = NULL;
 }
 
 struct combine_diff_state {
@@ -168,25 +164,28 @@ static void consume_line(void *state_, char *line, unsigned long len)
 				      &state->nb, &state->nn))
 			return;
 		state->lno = state->nb;
-		if (!state->nb)
-			/* @@ -1,2 +0,0 @@ to remove the
-			 * first two lines...
-			 */
-			state->nb = 1;
-		if (state->nn == 0)
+		if (state->nn == 0) {
 			/* @@ -X,Y +N,0 @@ removed Y lines
 			 * that would have come *after* line N
 			 * in the result.  Our lost buckets hang
 			 * to the line after the removed lines,
+			 *
+			 * Note that this is correct even when N == 0,
+			 * in which case the hunk removes the first
+			 * line in the file.
 			 */
 			state->lost_bucket = &state->sline[state->nb];
-		else
+			if (!state->nb)
+				state->nb = 1;
+		} else {
 			state->lost_bucket = &state->sline[state->nb-1];
+		}
 		if (!state->sline[state->nb-1].p_lno)
 			state->sline[state->nb-1].p_lno =
 				xcalloc(state->num_parent,
 					sizeof(unsigned long));
 		state->sline[state->nb-1].p_lno[state->n] = state->ob;
+		state->lost_bucket->next_lost = state->lost_bucket->lost_head;
 		return;
 	}
 	if (!state->lost_bucket)
diff --git a/t/t4038-diff-combined.sh b/t/t4038-diff-combined.sh
new file mode 100755
index 0000000000..2cf7e01ac2
--- /dev/null
+++ b/t/t4038-diff-combined.sh
@@ -0,0 +1,84 @@
+#!/bin/sh
+
+test_description='combined diff'
+
+. ./test-lib.sh
+
+setup_helper () {
+	one=$1 branch=$2 side=$3 &&
+
+	git branch $side $branch &&
+	for l in $one two three fyra
+	do
+		echo $l
+	done >file &&
+	git add file &&
+	test_tick &&
+	git commit -m $branch &&
+	git checkout $side &&
+	for l in $one two three quatro
+	do
+		echo $l
+	done >file &&
+	git add file &&
+	test_tick &&
+	git commit -m $side &&
+	test_must_fail git merge $branch &&
+	for l in $one three four
+	do
+		echo $l
+	done >file &&
+	git add file &&
+	test_tick &&
+	git commit -m "merge $branch into $side"
+}
+
+verify_helper () {
+	it=$1 &&
+
+	# Ignore lines that were removed only from the other parent
+	sed -e '
+		1,/^@@@/d
+		/^ -/d
+		s/^\(.\)./\1/
+	' "$it" >"$it.actual.1" &&
+	sed -e '
+		1,/^@@@/d
+		/^- /d
+		s/^.\(.\)/\1/
+	' "$it" >"$it.actual.2" &&
+
+	git diff "$it^" "$it" -- | sed -e '1,/^@@/d' >"$it.expect.1" &&
+	test_cmp "$it.expect.1" "$it.actual.1" &&
+
+	git diff "$it^2" "$it" -- | sed -e '1,/^@@/d' >"$it.expect.2" &&
+	test_cmp "$it.expect.2" "$it.actual.2"
+}
+
+test_expect_success setup '
+	>file &&
+	git add file &&
+	test_tick &&
+	git commit -m initial &&
+
+	git branch withone &&
+	git branch sansone &&
+
+	git checkout withone &&
+	setup_helper one withone sidewithone &&
+
+	git checkout sansone &&
+	setup_helper "" sansone sidesansone
+'
+
+test_expect_success 'check combined output (1)' '
+	git show sidewithone -- >sidewithone &&
+	verify_helper sidewithone
+'
+
+test_expect_failure 'check combined output (2)' '
+	git show sidesansone -- >sidesansone &&
+	verify_helper sidesansone
+'
+
+test_done
diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
index f83322e513..5698a9a736 100755
--- a/t/t4124-apply-ws-rule.sh
+++ b/t/t4124-apply-ws-rule.sh
@@ -148,4 +148,22 @@ do
 	done
 done
 
+create_patch () {
+	sed -e "s/_/ /" <<-\EOF
+		diff --git a/target b/target
+		index e69de29..8bd6648 100644
+		--- a/target
+		+++ b/target
+		@@ -0,0 +1 @@
+		+A line with trailing whitespace and no newline_
+		\ No newline at end of file
+	EOF
+}
+
+test_expect_success 'trailing whitespace & no newline at the end of file' '
+	>target &&
+	create_patch | git apply --whitespace=fix - &&
+	grep "newline$" target
+'
+
 test_done
diff --git a/ws.c b/ws.c
index 819c797cf6..8d855b7fd5 100644
--- a/ws.c
+++ b/ws.c
@@ -261,9 +261,8 @@ int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *erro
 	/*
 	 * Strip trailing whitespace
 	 */
-	if ((ws_rule & WS_TRAILING_SPACE) &&
-	    (2 <= len && isspace(src[len-2]))) {
-		if (src[len - 1] == '\n') {
+	if (ws_rule & WS_TRAILING_SPACE) {
+		if (1 < len && src[len - 1] == '\n') {
 			add_nl_to_tail = 1;
 			len--;
 			if (1 < len && src[len - 1] == '\r') {