Add documentation for git-pack-intersect

diff --git a/setup.c b/setup.c
index 453bddbb17365c8b090757c544edcc0a61fc96fb..c487d7eb9de70c651ef06a6bfd4a7571337fad84 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -1,23 +1,60 @@
 #include "cache.h"
 
-const char **get_pathspec(const char *prefix, char **pathspec)
+const char *prefix_path(const char *prefix, int len, const char *path)
 {
-       char *entry = *pathspec;
-       char **p;
-       int prefixlen;
-
-       if (!prefix) {
-               char **p;
-               if (!entry)
-                       return NULL;
-               p = pathspec;
+       const char *orig = path;
+       for (;;) {
+               char c;
+               if (*path != '.')
+                       break;
+               c = path[1];
+               /* "." */
+               if (!c) {
+                       path++;
+                       break;
+               }
+               /* "./" */
+               if (c == '/') {
+                       path += 2;
+                       continue;
+               }
+               if (c != '.')
+                       break;
+               c = path[2];
+               if (!c)
+                       path += 2;
+               else if (c == '/')
+                       path += 3;
+               else
+                       break;
+               /* ".." and "../" */
+               /* Remove last component of the prefix */
                do {
-                       if (*entry != '.')
-                               continue;
-                       /* fixup ? */
-               } while ((entry = *++p) != NULL);
-               return (const char **) pathspec;
+                       if (!len)
+                               die("'%s' is outside repository", orig);
+                       len--;
+               } while (len && prefix[len-1] != '/');
+               continue;
+       }
+       if (len) {
+               int speclen = strlen(path);
+               char *n = xmalloc(speclen + len + 1);
+       
+               memcpy(n, prefix, len);
+               memcpy(n + len, path, speclen+1);
+               path = n;
        }
+       return path;
+}
+
+const char **get_pathspec(const char *prefix, const char **pathspec)
+{
+       const char *entry = *pathspec;
+       const char **p;
+       int prefixlen;
+
+       if (!prefix && !entry)
+               return NULL;
 
        if (!entry) {
                static const char *spec[2];
@@ -27,42 +64,34 @@ const char **get_pathspec(const char *prefix, char **pathspec)
        }
 
        /* Otherwise we have to re-write the entries.. */
-       prefixlen = strlen(prefix);
        p = pathspec;
+       prefixlen = prefix ? strlen(prefix) : 0;
        do {
-               int speclen, len = prefixlen;
-               char *n;
-
-               for (;;) {
-                       if (!strcmp(entry, ".")) {
-                               entry++;
-                               break;
-                       }
-                       if (!strncmp(entry, "./", 2)) {
-                               entry += 2;
-                               continue;
-                       }
-                       if (!strncmp(entry, "../", 3)) {
-                               do {
-                                       if (!len)
-                                               die("'%s' is outside repository", *p);
-                                       len--;
-                               } while (len && prefix[len-1] != '/');
-                               entry += 3;
-                               continue;
-                       }
-                       break;
-               }
-               speclen = strlen(entry);
-               n = xmalloc(speclen + len + 1);
-               
-               memcpy(n, prefix, len);
-               memcpy(n + len, entry, speclen+1);
-               *p = n;
+               *p = prefix_path(prefix, prefixlen, entry);
        } while ((entry = *++p) != NULL);
        return (const char **) pathspec;
 }
 
+/*
+ * Test it it looks like we're at the top
+ * level git directory. We want to see a
+ *
+ *  - either a .git/objects/ directory _or_ the proper
+ *    GIT_OBJECT_DIRECTORY environment variable
+ *  - a refs/ directory under ".git"
+ *  - either a HEAD symlink or a HEAD file that is formatted as
+ *    a proper "ref:".
+ */
+static int is_toplevel_directory(void)
+{
+       if (access(".git/refs/", X_OK) ||
+           access(getenv(DB_ENVIRONMENT) ?
+                  getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
+           validate_symref(".git/HEAD"))
+               return 0;
+       return 1;
+}
+
 const char *setup_git_directory(void)
 {
        static char cwd[PATH_MAX+1];
@@ -72,7 +101,7 @@ const char *setup_git_directory(void)
         * If GIT_DIR is set explicitly, we're not going
         * to do any discovery
         */
-       if (gitenv(GIT_DIR_ENVIRONMENT))
+       if (getenv(GIT_DIR_ENVIRONMENT))
                return NULL;
 
        if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
@@ -80,18 +109,8 @@ const char *setup_git_directory(void)
 
        offset = len = strlen(cwd);
        for (;;) {
-               /*
-                * We always want to see a .git/HEAD and a .git/refs/
-                * subdirectory
-                */
-               if (!access(".git/HEAD", R_OK) && !access(".git/refs/", X_OK)) {
-                       /*
-                        * Then we need either a GIT_OBJECT_DIRECTORY define
-                        * or a .git/objects/ directory
-                        */
-                       if (gitenv(DB_ENVIRONMENT) || !access(".git/objects/", X_OK))
-                               break;
-               }
+               if (is_toplevel_directory())
+                       break;
                chdir("..");
                do {
                        if (!offset)