From: Phillip Wood <phillip.wood@xxxxxxxxxxxxx>
When "add -p" parses diffs, it looks for context lines starting with a
single space. But when diff.suppressBlankEmpty is in effect, an empty
context line will omit the space, giving us a true empty line. This
confuses the parser, which is unable to split based on such a line.
It's tempting to say that we should just make sure that we generate a
diff without that option. However, although we do not parse hunks that
the user has manually edited with parse_diff() we do allow the user
to split such hunks. As POSIX calls the decision of whether to print the
space here "implementation-defined" we need to handle edited hunks where
empty context lines omit the space.
So let's handle both cases: a context line either starts with a space or
consists of a totally empty line by normalizing the first character to a
space when we parse them. Normalizing the first character rather than
changing the code to check for a space or newline will hopefully future
proof against introducing similar bugs if the code is changed.
Reported-by: Ilya Tumaykin <itumaykin@xxxxxxxxx>
Helped-by: Jeff King <peff@xxxxxxxx>
Signed-off-by: Phillip Wood <phillip.wood@xxxxxxxxxxxxx>
---
add-patch.c | 19 +++++++++++++------
t/t3701-add-interactive.sh | 19 +++++++++++++++++++
2 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/add-patch.c b/add-patch.c
index d8ea05ff108..8feb719483f 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -400,6 +400,12 @@ static void complete_file(char marker, struct hunk *hunk)
hunk->splittable_into++;
}
+/* Empty context lines may omit the leading ' ' */
+static int normalize_marker(const char *p)
+{
+ return p[0] == '\n' || (p[0] == '\r' && p[1] == '\n') ? ' ' : p[0];
+}
+
static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
{
struct strvec args = STRVEC_INIT;
@@ -485,6 +491,7 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
while (p != pend) {
char *eol = memchr(p, '\n', pend - p);
const char *deleted = NULL, *mode_change = NULL;
+ char ch = normalize_marker(p);
if (!eol)
eol = pend;
@@ -532,7 +539,7 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
* Start counting into how many hunks this one can be
* split
*/
- marker = *p;
+ marker = ch;
} else if (hunk == &file_diff->head &&
starts_with(p, "new file")) {
file_diff->added = 1;
@@ -586,10 +593,10 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
(int)(eol - (plain->buf + file_diff->head.start)),
plain->buf + file_diff->head.start);
- if ((marker == '-' || marker == '+') && *p == ' ')
+ if ((marker == '-' || marker == '+') && ch == ' ')
hunk->splittable_into++;
- if (marker && *p != '\\')
- marker = *p;
+ if (marker && ch != '\\')
+ marker = ch;
p = eol == pend ? pend : eol + 1;
hunk->end = p - plain->buf;
@@ -813,7 +820,7 @@ static int merge_hunks(struct add_p_state *s, struct file_diff *file_diff,
(int)(hunk->end - hunk->start),
plain + hunk->start);
- if (plain[overlap_end] != ' ')
+ if (normalize_marker(&plain[overlap_end]) != ' ')
return error(_("expected context line "
"#%d in\n%.*s"),
(int)(j + 1),
@@ -953,7 +960,7 @@ static int split_hunk(struct add_p_state *s, struct file_diff *file_diff,
context_line_count = 0;
while (splittable_into > 1) {
- ch = s->plain.buf[current];
+ ch = normalize_marker(&s->plain.buf[current]);
if (!ch)
BUG("buffer overrun while splitting hunks");
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 5d78868ac16..9a48933cecf 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -1164,4 +1164,23 @@ test_expect_success 'reset -p with unmerged files' '
test_must_be_empty staged
'
+test_expect_success 'hunk splitting works with diff.suppressBlankEmpty' '
+ test_config diff.suppressBlankEmpty true &&
+ write_script fake-editor.sh <<-\EOF &&
+ tr F G <"$1" >"$1.tmp" &&
+ mv "$1.tmp" "$1"
+ EOF
+
+ test_write_lines a b "" c d "" e f "" >file &&
+ git add file &&
+ test_write_lines A b "" c D "" e F "" >file &&
+ (
+ test_set_editor "$(pwd)/fake-editor.sh" &&
+ test_write_lines s n y e q | git add -p file
+ ) &&
+ git cat-file blob :file >actual &&
+ test_write_lines a b "" c D "" e G "" >expect &&
+ test_cmp expect actual
+'
+
test_done
--
gitgitgadget
