diff: avoid stack-buffer-read-overrun for very long name
[git/git.git] / diff-no-index.c
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1/*
2 * "diff --no-index" support
3 * Copyright (c) 2007 by Johannes Schindelin
4 * Copyright (c) 2008 by Junio C Hamano
5 */
6
7#include "cache.h"
8#include "color.h"
9#include "commit.h"
10#include "blob.h"
11#include "tag.h"
12#include "diff.h"
13#include "diffcore.h"
14#include "revision.h"
15#include "log-tree.h"
16#include "builtin.h"
c455c87c 17#include "string-list.h"
0569e9b8 18
c455c87c 19static int read_directory(const char *path, struct string_list *list)
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20{
21 DIR *dir;
22 struct dirent *e;
23
24 if (!(dir = opendir(path)))
25 return error("Could not open directory %s", path);
26
27 while ((e = readdir(dir)))
28 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
78a395d3 29 string_list_insert(list, e->d_name);
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30
31 closedir(dir);
32 return 0;
33}
34
35static int get_mode(const char *path, int *mode)
36{
37 struct stat st;
38
39 if (!path || !strcmp(path, "/dev/null"))
40 *mode = 0;
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41#ifdef _WIN32
42 else if (!strcasecmp(path, "nul"))
43 *mode = 0;
44#endif
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45 else if (!strcmp(path, "-"))
46 *mode = create_ce_mode(0666);
418566b6 47 else if (lstat(path, &st))
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48 return error("Could not access '%s'", path);
49 else
50 *mode = st.st_mode;
51 return 0;
52}
53
54static int queue_diff(struct diff_options *o,
55 const char *name1, const char *name2)
56{
57 int mode1 = 0, mode2 = 0;
58
59 if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
60 return -1;
61
62 if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
63 return error("file/directory conflict: %s, %s", name1, name2);
64
65 if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
66 char buffer1[PATH_MAX], buffer2[PATH_MAX];
183113a5
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67 struct string_list p1 = STRING_LIST_INIT_DUP;
68 struct string_list p2 = STRING_LIST_INIT_DUP;
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69 int len1 = 0, len2 = 0, i1, i2, ret = 0;
70
71 if (name1 && read_directory(name1, &p1))
72 return -1;
73 if (name2 && read_directory(name2, &p2)) {
c455c87c 74 string_list_clear(&p1, 0);
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75 return -1;
76 }
77
78 if (name1) {
79 len1 = strlen(name1);
80 if (len1 > 0 && name1[len1 - 1] == '/')
81 len1--;
82 memcpy(buffer1, name1, len1);
83 buffer1[len1++] = '/';
84 }
85
86 if (name2) {
87 len2 = strlen(name2);
88 if (len2 > 0 && name2[len2 - 1] == '/')
89 len2--;
90 memcpy(buffer2, name2, len2);
91 buffer2[len2++] = '/';
92 }
93
94 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
95 const char *n1, *n2;
96 int comp;
97
98 if (i1 == p1.nr)
99 comp = 1;
100 else if (i2 == p2.nr)
101 comp = -1;
102 else
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103 comp = strcmp(p1.items[i1].string,
104 p2.items[i2].string);
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105
106 if (comp > 0)
107 n1 = NULL;
108 else {
109 n1 = buffer1;
c455c87c 110 strncpy(buffer1 + len1, p1.items[i1++].string,
0569e9b8 111 PATH_MAX - len1);
48e510b6 112 buffer1[PATH_MAX-1] = 0;
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113 }
114
115 if (comp < 0)
116 n2 = NULL;
117 else {
118 n2 = buffer2;
c455c87c 119 strncpy(buffer2 + len2, p2.items[i2++].string,
0569e9b8 120 PATH_MAX - len2);
48e510b6 121 buffer2[PATH_MAX-1] = 0;
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122 }
123
124 ret = queue_diff(o, n1, n2);
125 }
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126 string_list_clear(&p1, 0);
127 string_list_clear(&p2, 0);
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128
129 return ret;
130 } else {
131 struct diff_filespec *d1, *d2;
132
133 if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
134 unsigned tmp;
135 const char *tmp_c;
136 tmp = mode1; mode1 = mode2; mode2 = tmp;
137 tmp_c = name1; name1 = name2; name2 = tmp_c;
138 }
139
140 if (!name1)
141 name1 = "/dev/null";
142 if (!name2)
143 name2 = "/dev/null";
144 d1 = alloc_filespec(name1);
145 d2 = alloc_filespec(name2);
146 fill_filespec(d1, null_sha1, mode1);
147 fill_filespec(d2, null_sha1, mode2);
148
149 diff_queue(&diff_queued_diff, d1, d2);
150 return 0;
151 }
152}
153
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154static int path_outside_repo(const char *path)
155{
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156 const char *work_tree;
157 size_t len;
158
159 if (!is_absolute_path(path))
160 return 0;
161 work_tree = get_git_work_tree();
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162 if (!work_tree)
163 return 1;
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164 len = strlen(work_tree);
165 if (strncmp(path, work_tree, len) ||
166 (path[len] != '\0' && path[len] != '/'))
167 return 1;
168 return 0;
169}
170
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171void diff_no_index(struct rev_info *revs,
172 int argc, const char **argv,
173 int nongit, const char *prefix)
174{
175 int i;
176 int no_index = 0;
177 unsigned options = 0;
178
179 /* Were we asked to do --no-index explicitly? */
180 for (i = 1; i < argc; i++) {
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181 if (!strcmp(argv[i], "--")) {
182 i++;
183 break;
184 }
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185 if (!strcmp(argv[i], "--no-index"))
186 no_index = 1;
187 if (argv[i][0] != '-')
188 break;
189 }
190
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191 if (!no_index && !nongit) {
192 /*
193 * Inside a git repository, without --no-index. Only
194 * when a path outside the repository is given,
195 * e.g. "git diff /var/tmp/[12]", or "git diff
196 * Makefile /var/tmp/Makefile", allow it to be used as
197 * a colourful "diff" replacement.
198 */
199 if ((argc != i + 2) ||
200 (!path_outside_repo(argv[i]) &&
201 !path_outside_repo(argv[i+1])))
202 return;
203 }
0569e9b8 204 if (argc != i + 2)
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205 usagef("git diff %s <path> <path>",
206 no_index ? "--no-index" : "[--no-index]");
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207
208 diff_setup(&revs->diffopt);
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209 for (i = 1; i < argc - 2; ) {
210 int j;
211 if (!strcmp(argv[i], "--no-index"))
212 i++;
a324fc45 213 else if (!strcmp(argv[i], "-q")) {
0569e9b8 214 options |= DIFF_SILENT_ON_REMOVED;
a324fc45
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215 i++;
216 }
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217 else if (!strcmp(argv[i], "--"))
218 i++;
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219 else {
220 j = diff_opt_parse(&revs->diffopt, argv + i, argc - i);
221 if (!j)
222 die("invalid diff option/value: %s", argv[i]);
223 i += j;
224 }
225 }
226
c6dbca08
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227 /*
228 * If the user asked for our exit code then don't start a
229 * pager or we would end up reporting its exit code instead.
230 */
231 if (!DIFF_OPT_TST(&revs->diffopt, EXIT_WITH_STATUS))
232 setup_pager();
233
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234 if (prefix) {
235 int len = strlen(prefix);
16dc36fe
NTND
236 const char *paths[3];
237 memset(paths, 0, sizeof(paths));
0569e9b8 238
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239 for (i = 0; i < 2; i++) {
240 const char *p = argv[argc - 2 + i];
241 /*
242 * stdin should be spelled as '-'; if you have
243 * path that is '-', spell it as ./-.
244 */
245 p = (strcmp(p, "-")
246 ? xstrdup(prefix_filename(prefix, len, p))
247 : p);
16dc36fe 248 paths[i] = p;
0569e9b8 249 }
16dc36fe 250 diff_tree_setup_paths(paths, &revs->diffopt);
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251 }
252 else
16dc36fe 253 diff_tree_setup_paths(argv + argc - 2, &revs->diffopt);
d61027b2 254 revs->diffopt.skip_stat_unmatch = 1;
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255 if (!revs->diffopt.output_format)
256 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
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257
258 DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
259 DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
260
261 revs->max_count = -2;
262 if (diff_setup_done(&revs->diffopt) < 0)
263 die("diff_setup_done failed");
264
66f13625
NTND
265 if (queue_diff(&revs->diffopt, revs->diffopt.pathspec.raw[0],
266 revs->diffopt.pathspec.raw[1]))
0569e9b8 267 exit(1);
a5a818ee 268 diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
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269 diffcore_std(&revs->diffopt);
270 diff_flush(&revs->diffopt);
271
272 /*
273 * The return code for --no-index imitates diff(1):
274 * 0 = no changes, 1 = changes, else error
275 */
276 exit(revs->diffopt.found_changes);
277}