Retire support for old environment variables.
[git] / setup.c
1 #include "cache.h"
2
3 char *prefix_path(const char *prefix, int len, char *path)
4 {
5         char *orig = path;
6         for (;;) {
7                 char c;
8                 if (*path != '.')
9                         break;
10                 c = path[1];
11                 /* "." */
12                 if (!c) {
13                         path++;
14                         break;
15                 }
16                 /* "./" */
17                 if (c == '/') {
18                         path += 2;
19                         continue;
20                 }
21                 if (c != '.')
22                         break;
23                 c = path[2];
24                 if (!c)
25                         path += 2;
26                 else if (c == '/')
27                         path += 3;
28                 else
29                         break;
30                 /* ".." and "../" */
31                 /* Remove last component of the prefix */
32                 do {
33                         if (!len)
34                                 die("'%s' is outside repository", orig);
35                         len--;
36                 } while (len && prefix[len-1] != '/');
37                 continue;
38         }
39         if (len) {
40                 int speclen = strlen(path);
41                 char *n = xmalloc(speclen + len + 1);
42         
43                 memcpy(n, prefix, len);
44                 memcpy(n + len, path, speclen+1);
45                 path = n;
46         }
47         return path;
48 }
49
50 const char **get_pathspec(const char *prefix, char **pathspec)
51 {
52         char *entry = *pathspec;
53         char **p;
54         int prefixlen;
55
56         if (!prefix && !entry)
57                 return NULL;
58
59         if (!entry) {
60                 static const char *spec[2];
61                 spec[0] = prefix;
62                 spec[1] = NULL;
63                 return spec;
64         }
65
66         /* Otherwise we have to re-write the entries.. */
67         p = pathspec;
68         prefixlen = prefix ? strlen(prefix) : 0;
69         do {
70                 *p = prefix_path(prefix, prefixlen, entry);
71         } while ((entry = *++p) != NULL);
72         return (const char **) pathspec;
73 }
74
75 /*
76  * Test it it looks like we're at the top
77  * level git directory. We want to see a
78  *
79  *  - a HEAD symlink and a refs/ directory under ".git"
80  *  - either a .git/objects/ directory _or_ the proper
81  *    GIT_OBJECT_DIRECTORY environment variable
82  */
83 static int is_toplevel_directory(void)
84 {
85         struct stat st;
86
87         return  !lstat(".git/HEAD", &st) &&
88                 S_ISLNK(st.st_mode) &&
89                 !access(".git/refs/", X_OK) &&
90                 (getenv(DB_ENVIRONMENT) || !access(".git/objects/", X_OK));
91 }
92
93 const char *setup_git_directory(void)
94 {
95         static char cwd[PATH_MAX+1];
96         int len, offset;
97
98         /*
99          * If GIT_DIR is set explicitly, we're not going
100          * to do any discovery
101          */
102         if (getenv(GIT_DIR_ENVIRONMENT))
103                 return NULL;
104
105         if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
106                 die("Unable to read current working directory");
107
108         offset = len = strlen(cwd);
109         for (;;) {
110                 if (is_toplevel_directory())
111                         break;
112                 chdir("..");
113                 do {
114                         if (!offset)
115                                 die("Not a git repository");
116                 } while (cwd[--offset] != '/');
117         }
118
119         if (offset == len)
120                 return NULL;
121
122         /* Make "offset" point to past the '/', and add a '/' at the end */
123         offset++;
124         cwd[len++] = '/';
125         cwd[len] = 0;
126         return cwd + offset;
127 }