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Commit 8fcd421

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Junio C Hamano
committed
Merge branch 'eb/apply' into next
* eb/apply: Implement limited context matching in git-apply.
2 parents 6b32ee2 + 4749588 commit 8fcd421

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-19
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2 files changed

+112
-19
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‎Documentation/git-apply.txt‎

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@ SYNOPSIS
1111
[verse]
1212
'git-apply' [--stat] [--numstat] [--summary] [--check] [--index] [--apply]
1313
[--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM]
14-
[--whitespace=<nowarn|warn|error|error-all|strip>]
14+
[-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>]
1515
[<patch>...]
1616

1717
DESCRIPTION
@@ -73,6 +73,12 @@ OPTIONS
7373
Remove <n> leading slashes from traditional diff paths. The
7474
default is 1.
7575

76+
-C<n>::
77+
Ensure at least <n> lines of surrounding context match before
78+
and after each change. When fewer lines of surrounding
79+
context exist they all most match. By default no context is
80+
ever ignored.
81+
7682
--apply::
7783
If you use any of the options marked ``Turns off
7884
"apply"'' above, git-apply reads and outputs the

‎apply.c‎

Lines changed: 105 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -32,8 +32,9 @@ static int apply = 1;
3232
static int no_add = 0;
3333
static int show_index_info = 0;
3434
static int line_termination = '\n';
35+
static unsigned long p_context = -1;
3536
static const char apply_usage[] =
36-
"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
37+
"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
3738

3839
static enum whitespace_eol {
3940
nowarn_whitespace,
@@ -100,6 +101,7 @@ static int max_change, max_len;
100101
static int linenr = 1;
101102

102103
struct fragment {
104+
unsigned long leading, trailing;
103105
unsigned long oldpos, oldlines;
104106
unsigned long newpos, newlines;
105107
const char *patch;
@@ -817,12 +819,15 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
817819
int added, deleted;
818820
int len = linelen(line, size), offset;
819821
unsigned long oldlines, newlines;
822+
unsigned long leading, trailing;
820823

821824
offset = parse_fragment_header(line, len, fragment);
822825
if (offset < 0)
823826
return -1;
824827
oldlines = fragment->oldlines;
825828
newlines = fragment->newlines;
829+
leading = 0;
830+
trailing = 0;
826831

827832
if (patch->is_new < 0) {
828833
patch->is_new = !oldlines;
@@ -860,10 +865,14 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
860865
case ' ':
861866
oldlines--;
862867
newlines--;
868+
if (!deleted && !added)
869+
leading++;
870+
trailing++;
863871
break;
864872
case '-':
865873
deleted++;
866874
oldlines--;
875+
trailing = 0;
867876
break;
868877
case '+':
869878
/*
@@ -887,6 +896,7 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
887896
}
888897
added++;
889898
newlines--;
899+
trailing = 0;
890900
break;
891901

892902
/* We allow "\ No newline at end of file". Depending
@@ -904,6 +914,9 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
904914
}
905915
if (oldlines || newlines)
906916
return -1;
917+
fragment->leading = leading;
918+
fragment->trailing = trailing;
919+
907920
/* If a fragment ends with an incomplete line, we failed to include
908921
* it in the above loop because we hit oldlines == newlines == 0
909922
* before seeing it.
@@ -1087,7 +1100,7 @@ static int read_old_data(struct stat *st, const char *path, void *buf, unsigned
10871100
}
10881101
}
10891102

1090-
static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1103+
static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
10911104
{
10921105
int i;
10931106
unsigned long start, backwards, forwards;
@@ -1148,6 +1161,7 @@ static int find_offset(const char *buf, unsigned long size, const char *fragment
11481161
n = (i >> 1)+1;
11491162
if (i & 1)
11501163
n = -n;
1164+
*lines = n;
11511165
return try;
11521166
}
11531167

@@ -1157,6 +1171,33 @@ static int find_offset(const char *buf, unsigned long size, const char *fragment
11571171
return -1;
11581172
}
11591173

1174+
static void remove_first_line(const char **rbuf, int *rsize)
1175+
{
1176+
const char *buf = *rbuf;
1177+
int size = *rsize;
1178+
unsigned long offset;
1179+
offset = 0;
1180+
while (offset <= size) {
1181+
if (buf[offset++] == '\n')
1182+
break;
1183+
}
1184+
*rsize = size - offset;
1185+
*rbuf = buf + offset;
1186+
}
1187+
1188+
static void remove_last_line(const char **rbuf, int *rsize)
1189+
{
1190+
const char *buf = *rbuf;
1191+
int size = *rsize;
1192+
unsigned long offset;
1193+
offset = size - 1;
1194+
while (offset > 0) {
1195+
if (buf[--offset] == '\n')
1196+
break;
1197+
}
1198+
*rsize = offset + 1;
1199+
}
1200+
11601201
struct buffer_desc {
11611202
char *buffer;
11621203
unsigned long size;
@@ -1192,7 +1233,10 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
11921233
int offset, size = frag->size;
11931234
char *old = xmalloc(size);
11941235
char *new = xmalloc(size);
1236+
const char *oldlines, *newlines;
11951237
int oldsize = 0, newsize = 0;
1238+
unsigned long leading, trailing;
1239+
int pos, lines;
11961240

11971241
while (size > 0) {
11981242
int len = linelen(patch, size);
@@ -1241,23 +1285,59 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
12411285
newsize--;
12421286
}
12431287
#endif
1244-
1245-
offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1246-
if (offset >= 0) {
1247-
int diff = newsize - oldsize;
1248-
unsigned long size = desc->size + diff;
1249-
unsigned long alloc = desc->alloc;
1250-
1251-
if (size > alloc) {
1252-
alloc = size + 8192;
1253-
desc->alloc = alloc;
1254-
buf = xrealloc(buf, alloc);
1255-
desc->buffer = buf;
1288+
1289+
oldlines = old;
1290+
newlines = new;
1291+
leading = frag->leading;
1292+
trailing = frag->trailing;
1293+
lines = 0;
1294+
pos = frag->newpos;
1295+
for (;;) {
1296+
offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
1297+
if (offset >= 0) {
1298+
int diff = newsize - oldsize;
1299+
unsigned long size = desc->size + diff;
1300+
unsigned long alloc = desc->alloc;
1301+
1302+
/* Warn if it was necessary to reduce the number
1303+
* of context lines.
1304+
*/
1305+
if ((leading != frag->leading) || (trailing != frag->trailing))
1306+
fprintf(stderr, "Context reduced to (%ld/%ld) to apply fragment at %d\n",
1307+
leading, trailing, pos + lines);
1308+
1309+
if (size > alloc) {
1310+
alloc = size + 8192;
1311+
desc->alloc = alloc;
1312+
buf = xrealloc(buf, alloc);
1313+
desc->buffer = buf;
1314+
}
1315+
desc->size = size;
1316+
memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1317+
memcpy(buf + offset, newlines, newsize);
1318+
offset = 0;
1319+
1320+
break;
1321+
}
1322+
1323+
/* Am I at my context limits? */
1324+
if ((leading <= p_context) && (trailing <= p_context))
1325+
break;
1326+
/* Reduce the number of context lines
1327+
* Reduce both leading and trailing if they are equal
1328+
* otherwise just reduce the larger context.
1329+
*/
1330+
if (leading >= trailing) {
1331+
remove_first_line(&oldlines, &oldsize);
1332+
remove_first_line(&newlines, &newsize);
1333+
pos--;
1334+
leading--;
1335+
}
1336+
if (trailing > leading) {
1337+
remove_last_line(&oldlines, &oldsize);
1338+
remove_last_line(&newlines, &newsize);
1339+
trailing--;
12561340
}
1257-
desc->size = size;
1258-
memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1259-
memcpy(buf + offset, new, newsize);
1260-
offset = 0;
12611341
}
12621342

12631343
free(old);
@@ -1882,6 +1962,7 @@ int main(int argc, char **argv)
18821962

18831963
for (i = 1; i < argc; i++) {
18841964
const char *arg = argv[i];
1965+
char *end;
18851966
int fd;
18861967

18871968
if (!strcmp(arg, "-")) {
@@ -1945,6 +2026,12 @@ int main(int argc, char **argv)
19452026
line_termination = 0;
19462027
continue;
19472028
}
2029+
if (!strncmp(arg, "-C", 2)) {
2030+
p_context = strtoul(arg + 2, &end, 0);
2031+
if (*end != '\0')
2032+
die("unrecognized context count '%s'", arg + 2);
2033+
continue;
2034+
}
19482035
if (!strncmp(arg, "--whitespace=", 13)) {
19492036
whitespace_option = arg + 13;
19502037
parse_whitespace_option(arg + 13);

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