@matheusbsbs / matheus-bagliano / commits / 757e75c81e

patch-id: fix scan_hunk_header on diffs with 1 line of before/after

Normally diffs will contain a hunk header of the format "@@ -2,2 +2,15 @@ code". However when there is only 1 line of change, the unified diff format allows for the second comma separated value to be omitted in either before or after line counts. This can produce hunk headers that look like "@@ -2 +2,18 @@ code" or "@@ -2,2 +2 @@ code". As a result, scan_hunk_header mistakenly returns the line number as line count, which then results in unpredictable parsing errors with the rest of the patch, including giving multiple lines of output for a single commit. Fix by explicitly setting line count to 1 when there is no comma, and add a test. apply.c contains this same logic except it is correct. A worthwhile future project might be to unify these two diff parsers so they both benefit from fixes. Signed-off-by: Jerry Zhang <jerry@skydio.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jerry Zhang committed Feb 1, 2022 at 20:19 UTC 757e75c81e4332e363b90a0534a657b1bb6546fa
2 files changed +37 -3
builtin/patch-id.c
+7 -2
@@ -32,8 +32,12 @@ static int scan_hunk_header(const char *p, int *p_before, int *p_after)
32 n = strspn(q, digits);
33 if (q[n] == ',') {
34 q += n + 1;
35 + *p_before = atoi(q);
36 n = strspn(q, digits);
37 + } else {
38 + *p_before = 1;
39 }
40 +
41 if (n == 0 || q[n] != ' ' || q[n+1] != '+')
42 return 0;
43
@@ -41,13 +45,14 @@ static int scan_hunk_header(const char *p, int *p_before, int *p_after)
45 n = strspn(r, digits);
46 if (r[n] == ',') {
47 r += n + 1;
48 + *p_after = atoi(r);
49 n = strspn(r, digits);
50 + } else {
51 + *p_after = 1;
52 }
53 if (n == 0)
54 return 0;
55
49 - *p_before = atoi(q);
50 - *p_after = atoi(r);
56 return 1;
57 }
58
t/t4204-patch-id.sh
+30 -1
@@ -38,7 +38,7 @@ calc_patch_id () {
38 shift
39 git patch-id "$@" >patch-id.output &&
40 sed "s/ .*//" patch-id.output >patch-id_"$patch_name" &&
41 - test_line_count -gt 0 patch-id_"$patch_name"
41 + test_line_count -eq 1 patch-id_"$patch_name"
42 }
43
44 get_top_diff () {
@@ -200,4 +200,33 @@ test_expect_success 'patch-id handles no-nl-at-eof markers' '
200 calc_patch_id withnl <withnl &&
201 test_cmp patch-id_nonl patch-id_withnl
202 '
203 +
204 +test_expect_success 'patch-id handles diffs with one line of before/after' '
205 + cat >diffu1 <<-\EOF &&
206 + diff --git a/bar b/bar
207 + index bdaf90f..31051f6 100644
208 + --- a/bar
209 + +++ b/bar
210 + @@ -2 +2,2 @@
211 + b
212 + +c
213 + diff --git a/car b/car
214 + index 00750ed..2ae5e34 100644
215 + --- a/car
216 + +++ b/car
217 + @@ -1 +1,2 @@
218 + 3
219 + +d
220 + diff --git a/foo b/foo
221 + index e439850..7146eb8 100644
222 + --- a/foo
223 + +++ b/foo
224 + @@ -2 +2,2 @@
225 + a
226 + +e
227 + EOF
228 + calc_patch_id diffu1 <diffu1 &&
229 + test_config patchid.stable true &&
230 + calc_patch_id diffu1stable <diffu1
231 +'
232 test_done