Use nonrelative paths instead of absolute paths for cloned repositories

Particularly for the "alternates" file, if one will be created, we
want a path that doesn't depend on the current directory, but we want
to retain any symlinks in the path as given and any in the user's view
of the current directory when the path was given.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-clone.c

@@ -76,7 +76,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, suffix[i]);
 		if (!stat(path, &st) && S_ISDIR(st.st_mode)) {
 			*is_bundle = 0;
-			return xstrdup(make_absolute_path(path));
+			return xstrdup(make_nonrelative_path(path));
 		}
 	}
 
@@ -85,7 +85,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, bundle_suffix[i]);
 		if (!stat(path, &st) && S_ISREG(st.st_mode)) {
 			*is_bundle = 1;
-			return xstrdup(make_absolute_path(path));
+			return xstrdup(make_nonrelative_path(path));
 		}
 	}
 

cache.h

@@ -524,6 +524,7 @@ static inline int is_absolute_path(const char *path)
 	return path[0] == '/';
 }
 const char *make_absolute_path(const char *path);
+const char *make_nonrelative_path(const char *path);
 
 /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
 extern int sha1_object_info(const unsigned char *, unsigned long *);

path.c

@@ -291,6 +291,42 @@ int adjust_shared_perm(const char *path)
 	return 0;
 }
 
+static const char *get_pwd_cwd(void)
+{
+	static char cwd[PATH_MAX + 1];
+	char *pwd;
+	struct stat cwd_stat, pwd_stat;
+	if (getcwd(cwd, PATH_MAX) == NULL)
+		return NULL;
+	pwd = getenv("PWD");
+	if (pwd && strcmp(pwd, cwd)) {
+		stat(cwd, &cwd_stat);
+		if (!stat(pwd, &pwd_stat) &&
+		    pwd_stat.st_dev == cwd_stat.st_dev &&
+		    pwd_stat.st_ino == cwd_stat.st_ino) {
+			strlcpy(cwd, pwd, PATH_MAX);
+		}
+	}
+	return cwd;
+}
+
+const char *make_nonrelative_path(const char *path)
+{
+	static char buf[PATH_MAX + 1];
+
+	if (path[0] == '/') {
+		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+			die ("Too long path: %.*s", 60, path);
+	} else {
+		const char *cwd = get_pwd_cwd();
+		if (!cwd)
+			die("Cannot determine the current working directory");
+		if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
+			die ("Too long path: %.*s", 60, path);
+	}
+	return buf;
+}
+
 /* We allow "recursive" symbolic links. Only within reason, though. */
 #define MAXDEPTH 5