ls-tree: major rewrite to do pathspec

diff --git a/path.c b/path.c
index f788028a63dbd9b34563d2589697f4b5d65b8648..2c077c0c8f7066c5338050ce890c0846adedf6bd 100644 (file)
--- a/path.c
+++ b/path.c
@@ -11,6 +11,7 @@
  * which is what it's designed for.
  */
 #include "cache.h"
+#include <pwd.h>
 
 static char pathname[PATH_MAX];
 static char bad_path[] = "/bad-path/";
@@ -41,12 +42,10 @@ char *mkpath(const char *fmt, ...)
 
 char *git_path(const char *fmt, ...)
 {
-       const char *git_dir;
+       const char *git_dir = get_git_dir();
        va_list args;
        unsigned len;
 
-       git_dir = getenv(GIT_DIR_ENVIRONMENT);
-       if (!git_dir) git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
        len = strlen(git_dir);
        if (len > PATH_MAX-100)
                return bad_path;
@@ -91,3 +90,118 @@ char *safe_strncpy(char *dest, const char *src, size_t n)
 
        return dest;
 }
+
+int validate_symref(const char *path)
+{
+       struct stat st;
+       char *buf, buffer[256];
+       int len, fd;
+
+       if (lstat(path, &st) < 0)
+               return -1;
+
+       /* Make sure it is a "refs/.." symlink */
+       if (S_ISLNK(st.st_mode)) {
+               len = readlink(path, buffer, sizeof(buffer)-1);
+               if (len >= 5 && !memcmp("refs/", buffer, 5))
+                       return 0;
+               return -1;
+       }
+
+       /*
+        * Anything else, just open it and try to see if it is a symbolic ref.
+        */
+       fd = open(path, O_RDONLY);
+       if (fd < 0)
+               return -1;
+       len = read(fd, buffer, sizeof(buffer)-1);
+       close(fd);
+
+       /*
+        * Is it a symbolic ref?
+        */
+       if (len < 4 || memcmp("ref:", buffer, 4))
+               return -1;
+       buf = buffer + 4;
+       len -= 4;
+       while (len && isspace(*buf))
+               buf++, len--;
+       if (len >= 5 && !memcmp("refs/", buf, 5))
+               return 0;
+       return -1;
+}
+
+static char *current_dir(void)
+{
+       return getcwd(pathname, sizeof(pathname));
+}
+
+static int user_chdir(char *path)
+{
+       char *dir = path;
+
+       if(*dir == '~') {               /* user-relative path */
+               struct passwd *pw;
+               char *slash = strchr(dir, '/');
+
+               dir++;
+               /* '~/' and '~' (no slash) means users own home-dir */
+               if(!*dir || *dir == '/')
+                       pw = getpwuid(getuid());
+               else {
+                       if (slash) {
+                               *slash = '\0';
+                               pw = getpwnam(dir);
+                               *slash = '/';
+                       }
+                       else
+                               pw = getpwnam(dir);
+               }
+
+               /* make sure we got something back that we can chdir() to */
+               if(!pw || chdir(pw->pw_dir) < 0)
+                       return -1;
+
+               if(!slash || !slash[1]) /* no path following username */
+                       return 0;
+
+               dir = slash + 1;
+       }
+
+       /* ~foo/path/to/repo is now path/to/repo and we're in foo's homedir */
+       if(chdir(dir) < 0)
+               return -1;
+
+       return 0;
+}
+
+char *enter_repo(char *path, int strict)
+{
+       if(!path)
+               return NULL;
+
+       if (strict) {
+               if (chdir(path) < 0)
+                       return NULL;
+       }
+       else {
+               if (!*path)
+                       ; /* happy -- no chdir */
+               else if (!user_chdir(path))
+                       ; /* happy -- as given */
+               else if (!user_chdir(mkpath("%s.git", path)))
+                       ; /* happy -- uemacs --> uemacs.git */
+               else
+                       return NULL;
+               (void)chdir(".git");
+       }
+
+       if(access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
+          validate_symref("HEAD") == 0) {
+               putenv("GIT_DIR=.");
+               check_repository_format();
+               return current_dir();
+       }
+
+       return NULL;
+}