Add a test showing that 'git repack' throws away grafted-away parents
[git] / builtin-diff-tree.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "log-tree.h"
5 #include "builtin.h"
6
7 static struct rev_info log_tree_opt;
8
9 static int diff_tree_commit_sha1(const unsigned char *sha1)
10 {
11         struct commit *commit = lookup_commit_reference(sha1);
12         if (!commit)
13                 return -1;
14         return log_tree_commit(&log_tree_opt, commit);
15 }
16
17 /* Diff one or more commits. */
18 static int stdin_diff_commit(struct commit *commit, char *line, int len)
19 {
20         unsigned char sha1[20];
21         if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
22                 /* Graft the fake parents locally to the commit */
23                 int pos = 41;
24                 struct commit_list **pptr, *parents;
25
26                 /* Free the real parent list */
27                 for (parents = commit->parents; parents; ) {
28                         struct commit_list *tmp = parents->next;
29                         free(parents);
30                         parents = tmp;
31                 }
32                 commit->parents = NULL;
33                 pptr = &(commit->parents);
34                 while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
35                         struct commit *parent = lookup_commit(sha1);
36                         if (parent) {
37                                 pptr = &commit_list_insert(parent, pptr)->next;
38                         }
39                         pos += 41;
40                 }
41         }
42         return log_tree_commit(&log_tree_opt, commit);
43 }
44
45 /* Diff two trees. */
46 static int stdin_diff_trees(struct tree *tree1, char *line, int len)
47 {
48         unsigned char sha1[20];
49         struct tree *tree2;
50         if (len != 82 || !isspace(line[40]) || get_sha1_hex(line + 41, sha1))
51                 return error("Need exactly two trees, separated by a space");
52         tree2 = lookup_tree(sha1);
53         if (!tree2 || parse_tree(tree2))
54                 return -1;
55         printf("%s %s\n", sha1_to_hex(tree1->object.sha1),
56                           sha1_to_hex(tree2->object.sha1));
57         diff_tree_sha1(tree1->object.sha1, tree2->object.sha1,
58                        "", &log_tree_opt.diffopt);
59         log_tree_diff_flush(&log_tree_opt);
60         return 0;
61 }
62
63 static int diff_tree_stdin(char *line)
64 {
65         int len = strlen(line);
66         unsigned char sha1[20];
67         struct object *obj;
68
69         if (!len || line[len-1] != '\n')
70                 return -1;
71         line[len-1] = 0;
72         if (get_sha1_hex(line, sha1))
73                 return -1;
74         obj = lookup_unknown_object(sha1);
75         if (!obj || !obj->parsed)
76                 obj = parse_object(sha1);
77         if (!obj)
78                 return -1;
79         if (obj->type == OBJ_COMMIT)
80                 return stdin_diff_commit((struct commit *)obj, line, len);
81         if (obj->type == OBJ_TREE)
82                 return stdin_diff_trees((struct tree *)obj, line, len);
83         error("Object %s is a %s, not a commit or tree",
84               sha1_to_hex(sha1), typename(obj->type));
85         return -1;
86 }
87
88 static const char diff_tree_usage[] =
89 "git diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
90 "[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
91 "  -r            diff recursively\n"
92 "  --root        include the initial commit as diff against /dev/null\n"
93 COMMON_DIFF_OPTIONS_HELP;
94
95 int cmd_diff_tree(int argc, const char **argv, const char *prefix)
96 {
97         int nr_sha1;
98         char line[1000];
99         struct object *tree1, *tree2;
100         static struct rev_info *opt = &log_tree_opt;
101         int read_stdin = 0;
102
103         init_revisions(opt, prefix);
104         git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
105         opt->abbrev = 0;
106         opt->diff = 1;
107         argc = setup_revisions(argc, argv, opt, NULL);
108
109         while (--argc > 0) {
110                 const char *arg = *++argv;
111
112                 if (!strcmp(arg, "--stdin")) {
113                         read_stdin = 1;
114                         continue;
115                 }
116                 usage(diff_tree_usage);
117         }
118
119         if (!opt->diffopt.output_format)
120                 opt->diffopt.output_format = DIFF_FORMAT_RAW;
121
122         /*
123          * NOTE! We expect "a ^b" to be equal to "a..b", so we
124          * reverse the order of the objects if the second one
125          * is marked UNINTERESTING.
126          */
127         nr_sha1 = opt->pending.nr;
128         switch (nr_sha1) {
129         case 0:
130                 if (!read_stdin)
131                         usage(diff_tree_usage);
132                 break;
133         case 1:
134                 tree1 = opt->pending.objects[0].item;
135                 diff_tree_commit_sha1(tree1->sha1);
136                 break;
137         case 2:
138                 tree1 = opt->pending.objects[0].item;
139                 tree2 = opt->pending.objects[1].item;
140                 if (tree2->flags & UNINTERESTING) {
141                         struct object *tmp = tree2;
142                         tree2 = tree1;
143                         tree1 = tmp;
144                 }
145                 diff_tree_sha1(tree1->sha1,
146                                tree2->sha1,
147                                "", &opt->diffopt);
148                 log_tree_diff_flush(opt);
149                 break;
150         }
151
152         if (read_stdin) {
153                 if (opt->diffopt.detect_rename)
154                         opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
155                                                DIFF_SETUP_USE_CACHE);
156                 while (fgets(line, sizeof(line), stdin)) {
157                         unsigned char sha1[20];
158
159                         if (get_sha1_hex(line, sha1)) {
160                                 fputs(line, stdout);
161                                 fflush(stdout);
162                         }
163                         else
164                                 diff_tree_stdin(line);
165                 }
166         }
167
168         return diff_result_code(&opt->diffopt, 0);
169 }