Diff clean-up.
[git/git.git] / diff.c
CommitLineData
be3cfa85
JH
1/*
2 * Copyright (C) 2005 Junio C Hamano
3 */
4#include <sys/types.h>
5#include <sys/wait.h>
532149d7 6#include <signal.h>
86436c28 7#include "cache.h"
6fb737be 8#include "quote.h"
86436c28 9#include "diff.h"
427dcb4b 10#include "diffcore.h"
86436c28 11
d19938ab 12static const char *diff_opts = "-pu";
5c97558c 13static unsigned char null_sha1[20] = { 0, };
427dcb4b 14
f0c6b2a2 15static int use_size_cache;
86436c28 16
be3cfa85 17static const char *external_diff(void)
86436c28 18{
d19938ab 19 static const char *external_diff_cmd = NULL;
be3cfa85 20 static int done_preparing = 0;
c7c81b3a 21 const char *env_diff_opts;
be3cfa85
JH
22
23 if (done_preparing)
24 return external_diff_cmd;
25
86436c28
JH
26 /*
27 * Default values above are meant to match the
28 * Linux kernel development style. Examples of
29 * alternative styles you can specify via environment
30 * variables are:
31 *
86436c28
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32 * GIT_DIFF_OPTS="-c";
33 */
a9ab586a 34 external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
be3cfa85
JH
35
36 /* In case external diff fails... */
a9ab586a 37 env_diff_opts = getenv("GIT_DIFF_OPTS");
c7c81b3a 38 if (env_diff_opts) diff_opts = env_diff_opts;
be3cfa85
JH
39
40 done_preparing = 1;
41 return external_diff_cmd;
86436c28
JH
42}
43
64f8a631
HE
44#define TEMPFILE_PATH_LEN 50
45
be3cfa85 46static struct diff_tempfile {
427dcb4b 47 const char *name; /* filename external diff should read from */
be3cfa85
JH
48 char hex[41];
49 char mode[10];
64f8a631 50 char tmp_path[TEMPFILE_PATH_LEN];
be3cfa85
JH
51} diff_temp[2];
52
366175ef
JH
53static int count_lines(const char *filename)
54{
55 FILE *in;
56 int count, ch, completely_empty = 1, nl_just_seen = 0;
57 in = fopen(filename, "r");
58 count = 0;
59 while ((ch = fgetc(in)) != EOF)
60 if (ch == '\n') {
61 count++;
62 nl_just_seen = 1;
63 completely_empty = 0;
64 }
65 else {
66 nl_just_seen = 0;
67 completely_empty = 0;
68 }
69 fclose(in);
70 if (completely_empty)
71 return 0;
72 if (!nl_just_seen)
73 count++; /* no trailing newline */
74 return count;
75}
76
77static void print_line_count(int count)
78{
79 switch (count) {
80 case 0:
81 printf("0,0");
82 break;
83 case 1:
84 printf("1");
85 break;
86 default:
87 printf("1,%d", count);
88 break;
89 }
90}
91
92static void copy_file(int prefix, const char *filename)
93{
94 FILE *in;
95 int ch, nl_just_seen = 1;
96 in = fopen(filename, "r");
97 while ((ch = fgetc(in)) != EOF) {
98 if (nl_just_seen)
99 putchar(prefix);
100 putchar(ch);
101 if (ch == '\n')
102 nl_just_seen = 1;
103 else
104 nl_just_seen = 0;
105 }
106 fclose(in);
107 if (!nl_just_seen)
108 printf("\n\\ No newline at end of file\n");
109}
110
111static void emit_rewrite_diff(const char *name_a,
112 const char *name_b,
113 struct diff_tempfile *temp)
114{
115 /* Use temp[i].name as input, name_a and name_b as labels */
116 int lc_a, lc_b;
117 lc_a = count_lines(temp[0].name);
118 lc_b = count_lines(temp[1].name);
119 printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
120 print_line_count(lc_a);
121 printf(" +");
122 print_line_count(lc_b);
123 printf(" @@\n");
124 if (lc_a)
125 copy_file('-', temp[0].name);
126 if (lc_b)
127 copy_file('+', temp[1].name);
128}
129
915838c3
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130static void builtin_diff(const char *name_a,
131 const char *name_b,
57fe64a4 132 struct diff_tempfile *temp,
366175ef
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133 const char *xfrm_msg,
134 int complete_rewrite)
86436c28 135{
9669e17a 136 int i, next_at, cmd_size;
79db12e8
JH
137 const char *const diff_cmd = "diff -L%s%s -L%s%s";
138 const char *const diff_arg = "%s %s||:"; /* "||:" is to return 0 */
2f978138
JH
139 const char *input_name_sq[2];
140 const char *path0[2];
141 const char *path1[2];
915838c3 142 const char *name_sq[2];
2f978138 143 char *cmd;
915838c3 144
6fb737be
JH
145 name_sq[0] = sq_quote(name_a);
146 name_sq[1] = sq_quote(name_b);
915838c3 147
c983370e
JH
148 /* diff_cmd and diff_arg have 6 %s in total which makes
149 * the sum of these strings 12 bytes larger than required.
be3cfa85 150 * we use 2 spaces around diff-opts, and we need to count
c983370e 151 * terminating NUL, so we subtract 9 here.
be3cfa85 152 */
9669e17a 153 cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
c983370e 154 strlen(diff_arg) - 9);
2f978138 155 for (i = 0; i < 2; i++) {
6fb737be 156 input_name_sq[i] = sq_quote(temp[i].name);
2f978138
JH
157 if (!strcmp(temp[i].name, "/dev/null")) {
158 path0[i] = "/dev/null";
159 path1[i] = "";
2f978138 160 } else {
0980d9b3 161 path0[i] = i ? "b/" : "a/";
915838c3 162 path1[i] = name_sq[i];
2f978138
JH
163 }
164 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
c983370e 165 strlen(input_name_sq[i]));
2f978138 166 }
be3cfa85 167
2f978138
JH
168 cmd = xmalloc(cmd_size);
169
170 next_at = 0;
be3cfa85 171 next_at += snprintf(cmd+next_at, cmd_size-next_at,
2f978138 172 diff_cmd,
c983370e 173 path0[0], path1[0], path0[1], path1[1]);
be3cfa85
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174 next_at += snprintf(cmd+next_at, cmd_size-next_at,
175 " %s ", diff_opts);
176 next_at += snprintf(cmd+next_at, cmd_size-next_at,
2f978138
JH
177 diff_arg, input_name_sq[0], input_name_sq[1]);
178
915838c3 179 printf("diff --git a/%s b/%s\n", name_a, name_b);
70aadac0 180 if (!path1[0][0]) {
b58f23b3 181 printf("new file mode %s\n", temp[1].mode);
70aadac0
JH
182 if (xfrm_msg && xfrm_msg[0])
183 puts(xfrm_msg);
184 }
185 else if (!path1[1][0]) {
b58f23b3 186 printf("deleted file mode %s\n", temp[0].mode);
70aadac0
JH
187 if (xfrm_msg && xfrm_msg[0])
188 puts(xfrm_msg);
189 }
273b9834 190 else {
b58f23b3
JH
191 if (strcmp(temp[0].mode, temp[1].mode)) {
192 printf("old mode %s\n", temp[0].mode);
193 printf("new mode %s\n", temp[1].mode);
194 }
427dcb4b 195 if (xfrm_msg && xfrm_msg[0])
09d9d1a6 196 puts(xfrm_msg);
273b9834
JH
197 if (strncmp(temp[0].mode, temp[1].mode, 3))
198 /* we do not run diff between different kind
199 * of objects.
200 */
b28858bf 201 exit(0);
366175ef
JH
202 if (complete_rewrite) {
203 fflush(NULL);
204 emit_rewrite_diff(name_a, name_b, temp);
205 exit(0);
206 }
b28858bf 207 }
c983370e 208 fflush(NULL);
be3cfa85 209 execlp("/bin/sh","sh", "-c", cmd, NULL);
86436c28
JH
210}
211
427dcb4b
JH
212struct diff_filespec *alloc_filespec(const char *path)
213{
214 int namelen = strlen(path);
215 struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
705a7148
LT
216
217 memset(spec, 0, sizeof(*spec));
427dcb4b 218 spec->path = (char *)(spec + 1);
705a7148 219 memcpy(spec->path, path, namelen+1);
427dcb4b
JH
220 return spec;
221}
222
223void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
224 unsigned short mode)
225{
4130b995
JH
226 if (mode) {
227 spec->mode = DIFF_FILE_CANON_MODE(mode);
81e50eab
JH
228 memcpy(spec->sha1, sha1, 20);
229 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
230 }
427dcb4b
JH
231}
232
b46f0b6d
JH
233/*
234 * Given a name and sha1 pair, if the dircache tells us the file in
235 * the work tree has that object contents, return true, so that
236 * prepare_temp_file() does not have to inflate and extract.
237 */
238static int work_tree_matches(const char *name, const unsigned char *sha1)
239{
240 struct cache_entry *ce;
241 struct stat st;
242 int pos, len;
5c97558c 243
b46f0b6d
JH
244 /* We do not read the cache ourselves here, because the
245 * benchmark with my previous version that always reads cache
246 * shows that it makes things worse for diff-tree comparing
247 * two linux-2.6 kernel trees in an already checked out work
915838c3 248 * tree. This is because most diff-tree comparisons deal with
b46f0b6d
JH
249 * only a small number of files, while reading the cache is
250 * expensive for a large project, and its cost outweighs the
251 * savings we get by not inflating the object to a temporary
252 * file. Practically, this code only helps when we are used
253 * by diff-cache --cached, which does read the cache before
254 * calling us.
57fe64a4 255 */
b46f0b6d
JH
256 if (!active_cache)
257 return 0;
258
259 len = strlen(name);
260 pos = cache_name_pos(name, len);
261 if (pos < 0)
262 return 0;
263 ce = active_cache[pos];
b28858bf 264 if ((lstat(name, &st) < 0) ||
427dcb4b 265 !S_ISREG(st.st_mode) || /* careful! */
5d728c84 266 ce_match_stat(ce, &st) ||
b46f0b6d
JH
267 memcmp(sha1, ce->sha1, 20))
268 return 0;
427dcb4b
JH
269 /* we return 1 only when we can stat, it is a regular file,
270 * stat information matches, and sha1 recorded in the cache
271 * matches. I.e. we know the file in the work tree really is
272 * the same as the <name, sha1> pair.
273 */
b46f0b6d
JH
274 return 1;
275}
276
f0c6b2a2
JH
277static struct sha1_size_cache {
278 unsigned char sha1[20];
279 unsigned long size;
280} **sha1_size_cache;
281static int sha1_size_cache_nr, sha1_size_cache_alloc;
282
283static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
0601e131 284 int find_only,
f0c6b2a2
JH
285 unsigned long size)
286{
287 int first, last;
288 struct sha1_size_cache *e;
289
290 first = 0;
291 last = sha1_size_cache_nr;
292 while (last > first) {
0601e131 293 int cmp, next = (last + first) >> 1;
f0c6b2a2 294 e = sha1_size_cache[next];
0601e131 295 cmp = memcmp(e->sha1, sha1, 20);
f0c6b2a2
JH
296 if (!cmp)
297 return e;
298 if (cmp < 0) {
299 last = next;
300 continue;
301 }
302 first = next+1;
303 }
304 /* not found */
0601e131 305 if (find_only)
f0c6b2a2
JH
306 return NULL;
307 /* insert to make it at "first" */
308 if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
309 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
310 sha1_size_cache = xrealloc(sha1_size_cache,
311 sha1_size_cache_alloc *
312 sizeof(*sha1_size_cache));
313 }
314 sha1_size_cache_nr++;
315 if (first < sha1_size_cache_nr)
316 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
317 (sha1_size_cache_nr - first - 1) *
318 sizeof(*sha1_size_cache));
319 e = xmalloc(sizeof(struct sha1_size_cache));
320 sha1_size_cache[first] = e;
321 memcpy(e->sha1, sha1, 20);
322 e->size = size;
323 return e;
324}
325
427dcb4b
JH
326/*
327 * While doing rename detection and pickaxe operation, we may need to
328 * grab the data for the blob (or file) for our own in-core comparison.
329 * diff_filespec has data and size fields for this purpose.
330 */
f0c6b2a2 331int diff_populate_filespec(struct diff_filespec *s, int size_only)
427dcb4b
JH
332{
333 int err = 0;
81e50eab 334 if (!DIFF_FILE_VALID(s))
427dcb4b
JH
335 die("internal error: asking to populate invalid file.");
336 if (S_ISDIR(s->mode))
337 return -1;
338
f0c6b2a2
JH
339 if (!use_size_cache)
340 size_only = 0;
341
427dcb4b
JH
342 if (s->data)
343 return err;
344 if (!s->sha1_valid ||
345 work_tree_matches(s->path, s->sha1)) {
346 struct stat st;
347 int fd;
348 if (lstat(s->path, &st) < 0) {
349 if (errno == ENOENT) {
350 err_empty:
351 err = -1;
352 empty:
353 s->data = "";
354 s->size = 0;
355 return err;
356 }
357 }
358 s->size = st.st_size;
359 if (!s->size)
360 goto empty;
f0c6b2a2
JH
361 if (size_only)
362 return 0;
427dcb4b
JH
363 if (S_ISLNK(st.st_mode)) {
364 int ret;
365 s->data = xmalloc(s->size);
366 s->should_free = 1;
367 ret = readlink(s->path, s->data, s->size);
368 if (ret < 0) {
369 free(s->data);
370 goto err_empty;
371 }
372 return 0;
373 }
374 fd = open(s->path, O_RDONLY);
375 if (fd < 0)
376 goto err_empty;
377 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
427dcb4b 378 close(fd);
e35f9824
PR
379 if (s->data == MAP_FAILED)
380 goto err_empty;
381 s->should_munmap = 1;
427dcb4b
JH
382 }
383 else {
384 char type[20];
f0c6b2a2
JH
385 struct sha1_size_cache *e;
386
387 if (size_only) {
0601e131 388 e = locate_size_cache(s->sha1, 1, 0);
f0c6b2a2
JH
389 if (e) {
390 s->size = e->size;
391 return 0;
392 }
36e4d74a 393 if (!sha1_object_info(s->sha1, type, &s->size))
0601e131 394 locate_size_cache(s->sha1, 0, s->size);
65c2e0c3
JH
395 }
396 else {
397 s->data = read_sha1_file(s->sha1, type, &s->size);
398 s->should_free = 1;
f0c6b2a2 399 }
427dcb4b
JH
400 }
401 return 0;
402}
403
19397b45 404void diff_free_filespec_data(struct diff_filespec *s)
427dcb4b
JH
405{
406 if (s->should_free)
407 free(s->data);
408 else if (s->should_munmap)
409 munmap(s->data, s->size);
19397b45
JH
410 s->should_free = s->should_munmap = 0;
411 s->data = NULL;
427dcb4b
JH
412}
413
b28858bf
JH
414static void prep_temp_blob(struct diff_tempfile *temp,
415 void *blob,
416 unsigned long size,
417 unsigned char *sha1,
418 int mode)
419{
420 int fd;
421
64f8a631 422 fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
b28858bf
JH
423 if (fd < 0)
424 die("unable to create temp-file");
425 if (write(fd, blob, size) != size)
426 die("unable to write temp-file");
427 close(fd);
428 temp->name = temp->tmp_path;
429 strcpy(temp->hex, sha1_to_hex(sha1));
430 temp->hex[40] = 0;
431 sprintf(temp->mode, "%06o", mode);
432}
433
be3cfa85
JH
434static void prepare_temp_file(const char *name,
435 struct diff_tempfile *temp,
427dcb4b 436 struct diff_filespec *one)
86436c28 437{
81e50eab 438 if (!DIFF_FILE_VALID(one)) {
be3cfa85 439 not_a_valid_file:
532149d7
JH
440 /* A '-' entry produces this for file-2, and
441 * a '+' entry produces this for file-1.
442 */
be3cfa85
JH
443 temp->name = "/dev/null";
444 strcpy(temp->hex, ".");
445 strcpy(temp->mode, ".");
86436c28
JH
446 return;
447 }
be3cfa85 448
5c97558c 449 if (!one->sha1_valid ||
427dcb4b 450 work_tree_matches(name, one->sha1)) {
be3cfa85 451 struct stat st;
427dcb4b 452 if (lstat(name, &st) < 0) {
be3cfa85
JH
453 if (errno == ENOENT)
454 goto not_a_valid_file;
427dcb4b 455 die("stat(%s): %s", name, strerror(errno));
be3cfa85 456 }
b28858bf
JH
457 if (S_ISLNK(st.st_mode)) {
458 int ret;
459 char *buf, buf_[1024];
460 buf = ((sizeof(buf_) < st.st_size) ?
461 xmalloc(st.st_size) : buf_);
462 ret = readlink(name, buf, st.st_size);
463 if (ret < 0)
464 die("readlink(%s)", name);
465 prep_temp_blob(temp, buf, st.st_size,
466 (one->sha1_valid ?
427dcb4b 467 one->sha1 : null_sha1),
b28858bf
JH
468 (one->sha1_valid ?
469 one->mode : S_IFLNK));
470 }
471 else {
427dcb4b
JH
472 /* we can borrow from the file in the work tree */
473 temp->name = name;
b28858bf
JH
474 if (!one->sha1_valid)
475 strcpy(temp->hex, sha1_to_hex(null_sha1));
476 else
427dcb4b 477 strcpy(temp->hex, sha1_to_hex(one->sha1));
9d429ff6
JH
478 /* Even though we may sometimes borrow the
479 * contents from the work tree, we always want
480 * one->mode. mode is trustworthy even when
481 * !(one->sha1_valid), as long as
482 * DIFF_FILE_VALID(one).
483 */
484 sprintf(temp->mode, "%06o", one->mode);
b28858bf
JH
485 }
486 return;
be3cfa85
JH
487 }
488 else {
f0c6b2a2 489 if (diff_populate_filespec(one, 0))
427dcb4b
JH
490 die("cannot read data blob for %s", one->path);
491 prep_temp_blob(temp, one->data, one->size,
492 one->sha1, one->mode);
be3cfa85
JH
493 }
494}
495
496static void remove_tempfile(void)
497{
498 int i;
499
500 for (i = 0; i < 2; i++)
501 if (diff_temp[i].name == diff_temp[i].tmp_path) {
502 unlink(diff_temp[i].name);
503 diff_temp[i].name = NULL;
504 }
505}
506
532149d7
JH
507static void remove_tempfile_on_signal(int signo)
508{
509 remove_tempfile();
510}
511
be3cfa85
JH
512/* An external diff command takes:
513 *
514 * diff-cmd name infile1 infile1-sha1 infile1-mode \
5c97558c 515 * infile2 infile2-sha1 infile2-mode [ rename-to ]
be3cfa85
JH
516 *
517 */
4130b995
JH
518static void run_external_diff(const char *pgm,
519 const char *name,
5c97558c 520 const char *other,
427dcb4b
JH
521 struct diff_filespec *one,
522 struct diff_filespec *two,
366175ef
JH
523 const char *xfrm_msg,
524 int complete_rewrite)
be3cfa85
JH
525{
526 struct diff_tempfile *temp = diff_temp;
532149d7
JH
527 pid_t pid;
528 int status;
be3cfa85 529 static int atexit_asked = 0;
c7c81b3a 530 const char *othername;
be3cfa85 531
c7c81b3a 532 othername = (other? other : name);
77eb2720
JH
533 if (one && two) {
534 prepare_temp_file(name, &temp[0], one);
c7c81b3a 535 prepare_temp_file(othername, &temp[1], two);
77eb2720
JH
536 if (! atexit_asked &&
537 (temp[0].name == temp[0].tmp_path ||
538 temp[1].name == temp[1].tmp_path)) {
539 atexit_asked = 1;
540 atexit(remove_tempfile);
541 }
532149d7 542 signal(SIGINT, remove_tempfile_on_signal);
be3cfa85
JH
543 }
544
545 fflush(NULL);
546 pid = fork();
547 if (pid < 0)
548 die("unable to fork");
549 if (!pid) {
5c97558c
JH
550 if (pgm) {
551 if (one && two) {
427dcb4b 552 const char *exec_arg[10];
5c97558c
JH
553 const char **arg = &exec_arg[0];
554 *arg++ = pgm;
555 *arg++ = name;
556 *arg++ = temp[0].name;
557 *arg++ = temp[0].hex;
558 *arg++ = temp[0].mode;
559 *arg++ = temp[1].name;
560 *arg++ = temp[1].hex;
561 *arg++ = temp[1].mode;
427dcb4b 562 if (other) {
5c97558c 563 *arg++ = other;
427dcb4b
JH
564 *arg++ = xfrm_msg;
565 }
09d74b3b 566 *arg = NULL;
5c97558c
JH
567 execvp(pgm, (char *const*) exec_arg);
568 }
77eb2720
JH
569 else
570 execlp(pgm, pgm, name, NULL);
571 }
be3cfa85
JH
572 /*
573 * otherwise we use the built-in one.
574 */
77eb2720 575 if (one && two)
c7c81b3a 576 builtin_diff(name, othername, temp, xfrm_msg,
366175ef 577 complete_rewrite);
77eb2720
JH
578 else
579 printf("* Unmerged path %s\n", name);
be3cfa85
JH
580 exit(0);
581 }
6fa28064
JH
582 if (waitpid(pid, &status, 0) < 0 ||
583 !WIFEXITED(status) || WEXITSTATUS(status)) {
584 /* Earlier we did not check the exit status because
532149d7 585 * diff exits non-zero if files are different, and
6fa28064
JH
586 * we are not interested in knowing that. It was a
587 * mistake which made it harder to quit a diff-*
588 * session that uses the git-apply-patch-script as
589 * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
590 * should also exit non-zero only when it wants to
591 * abort the entire diff-* session.
532149d7
JH
592 */
593 remove_tempfile();
6fa28064
JH
594 fprintf(stderr, "external diff died, stopping at %s.\n", name);
595 exit(1);
532149d7 596 }
be3cfa85
JH
597 remove_tempfile();
598}
599
366175ef 600static void run_diff(struct diff_filepair *p)
4130b995
JH
601{
602 const char *pgm = external_diff();
366175ef
JH
603 char msg_[PATH_MAX*2+200], *xfrm_msg;
604 struct diff_filespec *one;
605 struct diff_filespec *two;
606 const char *name;
607 const char *other;
608 int complete_rewrite = 0;
609
610 if (DIFF_PAIR_UNMERGED(p)) {
611 /* unmerged */
612 run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
613 0);
614 return;
615 }
616
617 name = p->one->path;
618 other = (strcmp(name, p->two->path) ? p->two->path : NULL);
619 one = p->one; two = p->two;
620 switch (p->status) {
e7baa4f4 621 case DIFF_STATUS_COPIED:
366175ef
JH
622 sprintf(msg_,
623 "similarity index %d%%\n"
624 "copy from %s\n"
625 "copy to %s",
626 (int)(0.5 + p->score * 100.0/MAX_SCORE),
627 name, other);
628 xfrm_msg = msg_;
629 break;
e7baa4f4 630 case DIFF_STATUS_RENAMED:
366175ef
JH
631 sprintf(msg_,
632 "similarity index %d%%\n"
633 "rename from %s\n"
634 "rename to %s",
635 (int)(0.5 + p->score * 100.0/MAX_SCORE),
636 name, other);
637 xfrm_msg = msg_;
638 break;
e7baa4f4 639 case DIFF_STATUS_MODIFIED:
366175ef
JH
640 if (p->score) {
641 sprintf(msg_,
642 "dissimilarity index %d%%",
643 (int)(0.5 + p->score * 100.0/MAX_SCORE));
644 xfrm_msg = msg_;
645 complete_rewrite = 1;
646 break;
647 }
648 /* fallthru */
649 default:
650 xfrm_msg = NULL;
651 }
652
4130b995
JH
653 if (!pgm &&
654 DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
655 (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
656 /* a filepair that changes between file and symlink
657 * needs to be split into deletion and creation.
658 */
659 struct diff_filespec *null = alloc_filespec(two->path);
366175ef 660 run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
4130b995
JH
661 free(null);
662 null = alloc_filespec(one->path);
366175ef 663 run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
4130b995
JH
664 free(null);
665 }
666 else
366175ef
JH
667 run_external_diff(pgm, name, other, one, two, xfrm_msg,
668 complete_rewrite);
4130b995
JH
669}
670
6b5ee137 671void diff_setup(struct diff_options *options)
5c97558c 672{
6b5ee137
JH
673 memset(options, 0, sizeof(*options));
674 options->output_format = DIFF_FORMAT_RAW;
675 options->line_termination = '\n';
676 options->break_opt = -1;
677}
678
679int diff_setup_done(struct diff_options *options)
680{
681 if (options->find_copies_harder &&
682 options->detect_rename != DIFF_DETECT_COPY)
683 return -1;
684 if (options->setup & DIFF_SETUP_USE_CACHE) {
f0c6b2a2
JH
685 if (!active_cache)
686 /* read-cache does not die even when it fails
687 * so it is safe for us to do this here. Also
688 * it does not smudge active_cache or active_nr
689 * when it fails, so we do not have to worry about
690 * cleaning it up oufselves either.
691 */
692 read_cache();
693 }
6b5ee137 694 if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
f0c6b2a2 695 use_size_cache = 1;
6b5ee137
JH
696
697 return 0;
698}
699
700int diff_opt_parse(struct diff_options *options, const char **av, int ac)
701{
702 const char *arg = av[0];
703 if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
704 options->output_format = DIFF_FORMAT_PATCH;
705 else if (!strcmp(arg, "-z"))
706 options->line_termination = 0;
707 else if (!strcmp(arg, "--name-only"))
708 options->output_format = DIFF_FORMAT_NAME;
709 else if (!strcmp(arg, "-R"))
710 options->reverse_diff = 1;
711 else if (!strncmp(arg, "-S", 2))
712 options->pickaxe = arg + 2;
713 else if (!strcmp(arg, "-s"))
714 options->output_format = DIFF_FORMAT_NO_OUTPUT;
715 else if (!strncmp(arg, "-O", 2))
716 options->orderfile = arg + 2;
717 else if (!strncmp(arg, "--diff-filter=", 14))
718 options->filter = arg + 14;
719 else if (!strcmp(arg, "--pickaxe-all"))
720 options->pickaxe_opts = DIFF_PICKAXE_ALL;
721 else if (!strncmp(arg, "-B", 2)) {
722 if ((options->break_opt =
723 diff_scoreopt_parse(arg)) == -1)
724 return -1;
725 }
726 else if (!strncmp(arg, "-M", 2)) {
727 if ((options->rename_score =
728 diff_scoreopt_parse(arg)) == -1)
729 return -1;
730 options->detect_rename = DIFF_DETECT_RENAME;
731 }
732 else if (!strncmp(arg, "-C", 2)) {
733 if ((options->rename_score =
734 diff_scoreopt_parse(arg)) == -1)
735 return -1;
736 options->detect_rename = DIFF_DETECT_COPY;
737 }
738 else if (!strcmp(arg, "--find-copies-harder"))
739 options->find_copies_harder = 1;
740 else
741 return 0;
742 return 1;
5c97558c
JH
743}
744
0e3994fa
JH
745static int parse_num(const char **cp_p)
746{
747 int num, scale, ch, cnt;
748 const char *cp = *cp_p;
749
750 cnt = num = 0;
751 scale = 1;
752 while ('0' <= (ch = *cp) && ch <= '9') {
753 if (cnt++ < 5) {
754 /* We simply ignore more than 5 digits precision. */
755 scale *= 10;
756 num = num * 10 + ch - '0';
757 }
5de36bfe 758 cp++;
0e3994fa
JH
759 }
760 *cp_p = cp;
761
762 /* user says num divided by scale and we say internally that
763 * is MAX_SCORE * num / scale.
764 */
765 return (MAX_SCORE * num / scale);
766}
767
768int diff_scoreopt_parse(const char *opt)
769{
eeaa4603 770 int opt1, opt2, cmd;
0e3994fa
JH
771
772 if (*opt++ != '-')
773 return -1;
774 cmd = *opt++;
775 if (cmd != 'M' && cmd != 'C' && cmd != 'B')
776 return -1; /* that is not a -M, -C nor -B option */
777
778 opt1 = parse_num(&opt);
eeaa4603
JH
779 if (cmd != 'B')
780 opt2 = 0;
781 else {
782 if (*opt == 0)
783 opt2 = 0;
784 else if (*opt != '/')
785 return -1; /* we expect -B80/99 or -B80 */
786 else {
787 opt++;
788 opt2 = parse_num(&opt);
789 }
790 }
0e3994fa
JH
791 if (*opt != 0)
792 return -1;
eeaa4603 793 return opt1 | (opt2 << 16);
0e3994fa
JH
794}
795
6b14d7fa
JH
796struct diff_queue_struct diff_queued_diff;
797
798void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5c97558c 799{
6b14d7fa
JH
800 if (queue->alloc <= queue->nr) {
801 queue->alloc = alloc_nr(queue->alloc);
802 queue->queue = xrealloc(queue->queue,
803 sizeof(dp) * queue->alloc);
81e50eab 804 }
6b14d7fa 805 queue->queue[queue->nr++] = dp;
5c97558c
JH
806}
807
52e95789 808struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
6b14d7fa
JH
809 struct diff_filespec *one,
810 struct diff_filespec *two)
5c97558c 811{
52e95789 812 struct diff_filepair *dp = xmalloc(sizeof(*dp));
427dcb4b
JH
813 dp->one = one;
814 dp->two = two;
f7c1512a 815 dp->score = 0;
2210100a 816 dp->status = 0;
15d061b4 817 dp->source_stays = 0;
f345b0a0 818 dp->broken_pair = 0;
5098bafb
JH
819 if (queue)
820 diff_q(queue, dp);
427dcb4b 821 return dp;
5c97558c
JH
822}
823
226406f6
JH
824void diff_free_filepair(struct diff_filepair *p)
825{
19397b45
JH
826 diff_free_filespec_data(p->one);
827 diff_free_filespec_data(p->two);
5098bafb
JH
828 free(p->one);
829 free(p->two);
226406f6
JH
830 free(p);
831}
832
bceafe75
JH
833static void diff_flush_raw(struct diff_filepair *p,
834 int line_termination,
835 int inter_name_termination)
5c97558c 836{
b6d8f309
JH
837 int two_paths;
838 char status[10];
25d5ea41
JH
839
840 if (line_termination) {
79db12e8
JH
841 const char *const err =
842 "path %s cannot be expressed without -z";
25d5ea41
JH
843 if (strchr(p->one->path, line_termination) ||
844 strchr(p->one->path, inter_name_termination))
845 die(err, p->one->path);
846 if (strchr(p->two->path, line_termination) ||
847 strchr(p->two->path, inter_name_termination))
848 die(err, p->two->path);
849 }
850
366175ef
JH
851 if (p->score)
852 sprintf(status, "%c%03d", p->status,
853 (int)(0.5 + p->score * 100.0/MAX_SCORE));
854 else {
855 status[0] = p->status;
856 status[1] = 0;
857 }
b6d8f309 858 switch (p->status) {
e7baa4f4
JH
859 case DIFF_STATUS_COPIED:
860 case DIFF_STATUS_RENAMED:
b6d8f309 861 two_paths = 1;
b6d8f309 862 break;
e7baa4f4
JH
863 case DIFF_STATUS_ADDED:
864 case DIFF_STATUS_DELETED:
f345b0a0 865 two_paths = 0;
f345b0a0 866 break;
b6d8f309
JH
867 default:
868 two_paths = 0;
b6d8f309 869 break;
6b14d7fa 870 }
81e50eab
JH
871 printf(":%06o %06o %s ",
872 p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
b6d8f309
JH
873 printf("%s %s%c%s",
874 sha1_to_hex(p->two->sha1),
875 status,
876 inter_name_termination,
877 p->one->path);
878 if (two_paths)
879 printf("%c%s", inter_name_termination, p->two->path);
880 putchar(line_termination);
5c97558c
JH
881}
882
52f28529
JH
883static void diff_flush_name(struct diff_filepair *p,
884 int line_termination)
885{
886 printf("%s%c", p->two->path, line_termination);
887}
888
f7c1512a 889int diff_unmodified_pair(struct diff_filepair *p)
5c97558c 890{
427dcb4b
JH
891 /* This function is written stricter than necessary to support
892 * the currently implemented transformers, but the idea is to
52e95789 893 * let transformers to produce diff_filepairs any way they want,
427dcb4b 894 * and filter and clean them up here before producing the output.
5c97558c 895 */
6b14d7fa
JH
896 struct diff_filespec *one, *two;
897
898 if (DIFF_PAIR_UNMERGED(p))
899 return 0; /* unmerged is interesting */
5c97558c 900
6b14d7fa
JH
901 one = p->one;
902 two = p->two;
5c97558c 903
4130b995
JH
904 /* deletion, addition, mode or type change
905 * and rename are all interesting.
906 */
81e50eab 907 if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4130b995 908 DIFF_PAIR_MODE_CHANGED(p) ||
427dcb4b
JH
909 strcmp(one->path, two->path))
910 return 0;
57fe64a4 911
427dcb4b
JH
912 /* both are valid and point at the same path. that is, we are
913 * dealing with a change.
57fe64a4 914 */
427dcb4b
JH
915 if (one->sha1_valid && two->sha1_valid &&
916 !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
917 return 1; /* no change */
918 if (!one->sha1_valid && !two->sha1_valid)
919 return 1; /* both look at the same file on the filesystem. */
920 return 0;
57fe64a4
JH
921}
922
b6d8f309 923static void diff_flush_patch(struct diff_filepair *p)
f7c1512a 924{
f7c1512a
JH
925 if (diff_unmodified_pair(p))
926 return;
927
f7c1512a
JH
928 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
929 (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
930 return; /* no tree diffs in patch format */
931
366175ef 932 run_diff(p);
f7c1512a
JH
933}
934
bceafe75 935int diff_queue_is_empty(void)
f7c1512a 936{
bceafe75 937 struct diff_queue_struct *q = &diff_queued_diff;
25d5ea41
JH
938 int i;
939 for (i = 0; i < q->nr; i++)
940 if (!diff_unmodified_pair(q->queue[i]))
941 return 0;
942 return 1;
f7c1512a
JH
943}
944
25d5ea41
JH
945#if DIFF_DEBUG
946void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
947{
948 fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
c7c81b3a 949 x, one ? one : "",
25d5ea41
JH
950 s->path,
951 DIFF_FILE_VALID(s) ? "valid" : "invalid",
952 s->mode,
953 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
954 fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
c7c81b3a 955 x, one ? one : "",
25d5ea41
JH
956 s->size, s->xfrm_flags);
957}
958
959void diff_debug_filepair(const struct diff_filepair *p, int i)
960{
961 diff_debug_filespec(p->one, i, "one");
962 diff_debug_filespec(p->two, i, "two");
f345b0a0 963 fprintf(stderr, "score %d, status %c stays %d broken %d\n",
c7c81b3a 964 p->score, p->status ? p->status : '?',
f345b0a0 965 p->source_stays, p->broken_pair);
25d5ea41
JH
966}
967
968void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
6b14d7fa 969{
6b14d7fa 970 int i;
25d5ea41
JH
971 if (msg)
972 fprintf(stderr, "%s\n", msg);
973 fprintf(stderr, "q->nr = %d\n", q->nr);
6b14d7fa
JH
974 for (i = 0; i < q->nr; i++) {
975 struct diff_filepair *p = q->queue[i];
25d5ea41
JH
976 diff_debug_filepair(p, i);
977 }
978}
979#endif
980
981static void diff_resolve_rename_copy(void)
982{
983 int i, j;
984 struct diff_filepair *p, *pp;
985 struct diff_queue_struct *q = &diff_queued_diff;
986
25d5ea41
JH
987 diff_debug_queue("resolve-rename-copy", q);
988
989 for (i = 0; i < q->nr; i++) {
990 p = q->queue[i];
96716a19 991 p->status = 0; /* undecided */
bceafe75 992 if (DIFF_PAIR_UNMERGED(p))
e7baa4f4 993 p->status = DIFF_STATUS_UNMERGED;
15d061b4 994 else if (!DIFF_FILE_VALID(p->one))
e7baa4f4 995 p->status = DIFF_STATUS_ADDED;
2cd68882 996 else if (!DIFF_FILE_VALID(p->two))
e7baa4f4 997 p->status = DIFF_STATUS_DELETED;
96716a19 998 else if (DIFF_PAIR_TYPE_CHANGED(p))
e7baa4f4 999 p->status = DIFF_STATUS_TYPE_CHANGED;
96716a19
JH
1000
1001 /* from this point on, we are dealing with a pair
1002 * whose both sides are valid and of the same type, i.e.
1003 * either in-place edit or rename/copy edit.
1004 */
01c4e70f 1005 else if (DIFF_PAIR_RENAME(p)) {
15d061b4 1006 if (p->source_stays) {
e7baa4f4 1007 p->status = DIFF_STATUS_COPIED;
15d061b4
JH
1008 continue;
1009 }
1010 /* See if there is some other filepair that
1011 * copies from the same source as us. If so
6bac10d8
JH
1012 * we are a copy. Otherwise we are either a
1013 * copy if the path stays, or a rename if it
1014 * does not, but we already handled "stays" case.
25d5ea41 1015 */
15d061b4 1016 for (j = i + 1; j < q->nr; j++) {
25d5ea41
JH
1017 pp = q->queue[j];
1018 if (strcmp(pp->one->path, p->one->path))
15d061b4 1019 continue; /* not us */
01c4e70f 1020 if (!DIFF_PAIR_RENAME(pp))
15d061b4
JH
1021 continue; /* not a rename/copy */
1022 /* pp is a rename/copy from the same source */
e7baa4f4 1023 p->status = DIFF_STATUS_COPIED;
15d061b4 1024 break;
25d5ea41
JH
1025 }
1026 if (!p->status)
e7baa4f4 1027 p->status = DIFF_STATUS_RENAMED;
bceafe75 1028 }
9fdade06
JH
1029 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1030 p->one->mode != p->two->mode)
e7baa4f4 1031 p->status = DIFF_STATUS_MODIFIED;
67574c40
JH
1032 else {
1033 /* This is a "no-change" entry and should not
1034 * happen anymore, but prepare for broken callers.
15d061b4 1035 */
67574c40
JH
1036 error("feeding unmodified %s to diffcore",
1037 p->one->path);
e7baa4f4 1038 p->status = DIFF_STATUS_UNKNOWN;
67574c40 1039 }
6b14d7fa 1040 }
25d5ea41 1041 diff_debug_queue("resolve-rename-copy done", q);
38c6f780
JH
1042}
1043
6b5ee137 1044void diff_flush(struct diff_options *options)
38c6f780
JH
1045{
1046 struct diff_queue_struct *q = &diff_queued_diff;
1047 int i;
bceafe75 1048 int inter_name_termination = '\t';
6b5ee137
JH
1049 int diff_output_format = options->output_format;
1050 int line_termination = options->line_termination;
38c6f780 1051
e68b6f15
LT
1052 if (!line_termination)
1053 inter_name_termination = 0;
bceafe75 1054
f7c1512a 1055 for (i = 0; i < q->nr; i++) {
f7c1512a 1056 struct diff_filepair *p = q->queue[i];
6b5ee137 1057 if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
e7baa4f4 1058 (p->status == DIFF_STATUS_UNKNOWN))
96716a19 1059 continue;
bceafe75 1060 if (p->status == 0)
96716a19 1061 die("internal error in diff-resolve-rename-copy");
6b5ee137 1062 switch (diff_output_format) {
bceafe75 1063 case DIFF_FORMAT_PATCH:
b6d8f309 1064 diff_flush_patch(p);
bceafe75 1065 break;
e68b6f15 1066 case DIFF_FORMAT_RAW:
bceafe75
JH
1067 diff_flush_raw(p, line_termination,
1068 inter_name_termination);
1069 break;
52f28529 1070 case DIFF_FORMAT_NAME:
52f28529
JH
1071 diff_flush_name(p, line_termination);
1072 break;
bceafe75 1073 }
226406f6 1074 diff_free_filepair(q->queue[i]);
90a734dc 1075 }
427dcb4b
JH
1076 free(q->queue);
1077 q->queue = NULL;
1078 q->nr = q->alloc = 0;
5c97558c
JH
1079}
1080
f2ce9fde
JH
1081static void diffcore_apply_filter(const char *filter)
1082{
1083 int i;
1084 struct diff_queue_struct *q = &diff_queued_diff;
1085 struct diff_queue_struct outq;
1086 outq.queue = NULL;
1087 outq.nr = outq.alloc = 0;
1088
1089 if (!filter)
1090 return;
1091
e7baa4f4 1092 if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
f2ce9fde
JH
1093 int found;
1094 for (i = found = 0; !found && i < q->nr; i++) {
1095 struct diff_filepair *p = q->queue[i];
e7baa4f4
JH
1096 if (((p->status == DIFF_STATUS_MODIFIED) &&
1097 ((p->score &&
1098 strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1099 (!p->score &&
1100 strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1101 ((p->status != DIFF_STATUS_MODIFIED) &&
1102 strchr(filter, p->status)))
f2ce9fde
JH
1103 found++;
1104 }
1105 if (found)
1106 return;
1107
1108 /* otherwise we will clear the whole queue
1109 * by copying the empty outq at the end of this
1110 * function, but first clear the current entries
1111 * in the queue.
1112 */
1113 for (i = 0; i < q->nr; i++)
1114 diff_free_filepair(q->queue[i]);
1115 }
1116 else {
1117 /* Only the matching ones */
1118 for (i = 0; i < q->nr; i++) {
1119 struct diff_filepair *p = q->queue[i];
e7baa4f4
JH
1120
1121 if (((p->status == DIFF_STATUS_MODIFIED) &&
1122 ((p->score &&
1123 strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1124 (!p->score &&
1125 strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1126 ((p->status != DIFF_STATUS_MODIFIED) &&
1127 strchr(filter, p->status)))
f2ce9fde
JH
1128 diff_q(&outq, p);
1129 else
1130 diff_free_filepair(p);
1131 }
1132 }
1133 free(q->queue);
1134 *q = outq;
1135}
1136
6b5ee137 1137void diffcore_std(struct diff_options *options)
befe8639 1138{
6b5ee137
JH
1139 if (options->paths && options->paths[0])
1140 diffcore_pathspec(options->paths);
1141 if (options->break_opt != -1)
1142 diffcore_break(options->break_opt);
1143 if (options->detect_rename)
1144 diffcore_rename(options->detect_rename, options->rename_score);
1145 if (options->break_opt != -1)
eeaa4603 1146 diffcore_merge_broken();
6b5ee137
JH
1147 if (options->pickaxe)
1148 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1149 if (options->orderfile)
1150 diffcore_order(options->orderfile);
f2ce9fde 1151 diff_resolve_rename_copy();
6b5ee137 1152 diffcore_apply_filter(options->filter);
f2ce9fde
JH
1153}
1154
1155
6b5ee137 1156void diffcore_std_no_resolve(struct diff_options *options)
f2ce9fde 1157{
6b5ee137
JH
1158 if (options->pickaxe)
1159 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1160 if (options->orderfile)
1161 diffcore_order(options->orderfile);
1162 diffcore_apply_filter(options->filter);
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1163}
1164
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1165void diff_addremove(struct diff_options *options,
1166 int addremove, unsigned mode,
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1167 const unsigned char *sha1,
1168 const char *base, const char *path)
be3cfa85 1169{
77eb2720 1170 char concatpath[PATH_MAX];
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1171 struct diff_filespec *one, *two;
1172
1173 /* This may look odd, but it is a preparation for
1174 * feeding "there are unchanged files which should
1175 * not produce diffs, but when you are doing copy
1176 * detection you would need them, so here they are"
1177 * entries to the diff-core. They will be prefixed
1178 * with something like '=' or '*' (I haven't decided
1179 * which but should not make any difference).
f7c1512a 1180 * Feeding the same new and old to diff_change()
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1181 * also has the same effect.
1182 * Before the final output happens, they are pruned after
1183 * merged into rename/copy pairs as appropriate.
427dcb4b 1184 */
6b5ee137 1185 if (options->reverse_diff)
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1186 addremove = (addremove == '+' ? '-' :
1187 addremove == '-' ? '+' : addremove);
7ca45252 1188
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1189 if (!path) path = "";
1190 sprintf(concatpath, "%s%s", base, path);
1191 one = alloc_filespec(concatpath);
1192 two = alloc_filespec(concatpath);
be3cfa85 1193
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1194 if (addremove != '+')
1195 fill_filespec(one, sha1, mode);
1196 if (addremove != '-')
1197 fill_filespec(two, sha1, mode);
5c97558c 1198
38c6f780 1199 diff_queue(&diff_queued_diff, one, two);
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1200}
1201
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1202void diff_change(struct diff_options *options,
1203 unsigned old_mode, unsigned new_mode,
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1204 const unsigned char *old_sha1,
1205 const unsigned char *new_sha1,
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1206 const char *base, const char *path)
1207{
77eb2720 1208 char concatpath[PATH_MAX];
427dcb4b 1209 struct diff_filespec *one, *two;
77eb2720 1210
6b5ee137 1211 if (options->reverse_diff) {
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1212 unsigned tmp;
1213 const unsigned char *tmp_c;
1214 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1215 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1216 }
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1217 if (!path) path = "";
1218 sprintf(concatpath, "%s%s", base, path);
1219 one = alloc_filespec(concatpath);
1220 two = alloc_filespec(concatpath);
1221 fill_filespec(one, old_sha1, old_mode);
1222 fill_filespec(two, new_sha1, new_mode);
1223
38c6f780 1224 diff_queue(&diff_queued_diff, one, two);
77eb2720 1225}
be3cfa85 1226
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1227void diff_unmerge(struct diff_options *options,
1228 const char *path)
77eb2720 1229{
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1230 struct diff_filespec *one, *two;
1231 one = alloc_filespec(path);
1232 two = alloc_filespec(path);
1233 diff_queue(&diff_queued_diff, one, two);
86436c28 1234}