worktree: refactor find_linked_symref function

Refactoring will help transition this code to provide additional useful
worktree functions.

Signed-off-by: Michael Rappazzo <rappazzo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/worktree.c b/worktree.c
index 10e14960b2134eff5ca0940f70072fb16ba62731..3c2498ae1c3dc12f693bc92117ea7bfb82c34fbe 100644 (file)
--- a/worktree.c
+++ b/worktree.c
@@ -3,6 +3,64 @@
 #include "strbuf.h"
 #include "worktree.h"
 
+/*
+ * read 'path_to_ref' into 'ref'.  Also if is_detached is not NULL,
+ * set is_detached to 1 (0) if the ref is detatched (is not detached).
+ *
+ * $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside $GIT_DIR so
+ * for linked worktrees, `resolve_ref_unsafe()` won't work (it uses
+ * git_path). Parse the ref ourselves.
+ *
+ * return -1 if the ref is not a proper ref, 0 otherwise (success)
+ */
+static int parse_ref(char *path_to_ref, struct strbuf *ref, int *is_detached)
+{
+       if (is_detached)
+               *is_detached = 0;
+       if (!strbuf_readlink(ref, path_to_ref, 0)) {
+               /* HEAD is symbolic link */
+               if (!starts_with(ref->buf, "refs/") ||
+                               check_refname_format(ref->buf, 0))
+                       return -1;
+       } else if (strbuf_read_file(ref, path_to_ref, 0) >= 0) {
+               /* textual symref or detached */
+               if (!starts_with(ref->buf, "ref:")) {
+                       if (is_detached)
+                               *is_detached = 1;
+               } else {
+                       strbuf_remove(ref, 0, strlen("ref:"));
+                       strbuf_trim(ref);
+                       if (check_refname_format(ref->buf, 0))
+                               return -1;
+               }
+       } else
+               return -1;
+       return 0;
+}
+
+static char *find_main_symref(const char *symref, const char *branch)
+{
+       struct strbuf sb = STRBUF_INIT;
+       struct strbuf path = STRBUF_INIT;
+       struct strbuf gitdir = STRBUF_INIT;
+       char *existing = NULL;
+
+       strbuf_addf(&path, "%s/%s", get_git_common_dir(), symref);
+       if (parse_ref(path.buf, &sb, NULL) < 0)
+               goto done;
+       if (strcmp(sb.buf, branch))
+               goto done;
+       strbuf_addstr(&gitdir, get_git_common_dir());
+       strbuf_strip_suffix(&gitdir, ".git");
+       existing = strbuf_detach(&gitdir, NULL);
+done:
+       strbuf_release(&path);
+       strbuf_release(&sb);
+       strbuf_release(&gitdir);
+
+       return existing;
+}
+
 static char *find_linked_symref(const char *symref, const char *branch,
                                const char *id)
 {
@@ -11,36 +69,20 @@ static char *find_linked_symref(const char *symref, const char *branch,
        struct strbuf gitdir = STRBUF_INIT;
        char *existing = NULL;
 
-       /*
-        * $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside
-        * $GIT_DIR so resolve_ref_unsafe() won't work (it uses
-        * git_path). Parse the ref ourselves.
-        */
-       if (id)
-               strbuf_addf(&path, "%s/worktrees/%s/%s", get_git_common_dir(), id, symref);
-       else
-               strbuf_addf(&path, "%s/%s", get_git_common_dir(), symref);
+       if (!id)
+               die("Missing linked worktree name");
 
-       if (!strbuf_readlink(&sb, path.buf, 0)) {
-               if (!starts_with(sb.buf, "refs/") ||
-                   check_refname_format(sb.buf, 0))
-                       goto done;
-       } else if (strbuf_read_file(&sb, path.buf, 0) >= 0 &&
-           starts_with(sb.buf, "ref:")) {
-               strbuf_remove(&sb, 0, strlen("ref:"));
-               strbuf_trim(&sb);
-       } else
+       strbuf_addf(&path, "%s/worktrees/%s/%s", get_git_common_dir(), id, symref);
+
+       if (parse_ref(path.buf, &sb, NULL) < 0)
                goto done;
        if (strcmp(sb.buf, branch))
                goto done;
-       if (id) {
-               strbuf_reset(&path);
-               strbuf_addf(&path, "%s/worktrees/%s/gitdir", get_git_common_dir(), id);
-               if (strbuf_read_file(&gitdir, path.buf, 0) <= 0)
-                       goto done;
-               strbuf_rtrim(&gitdir);
-       } else
-               strbuf_addstr(&gitdir, get_git_common_dir());
+       strbuf_reset(&path);
+       strbuf_addf(&path, "%s/worktrees/%s/gitdir", get_git_common_dir(), id);
+       if (strbuf_read_file(&gitdir, path.buf, 0) <= 0)
+               goto done;
+       strbuf_rtrim(&gitdir);
        strbuf_strip_suffix(&gitdir, ".git");
 
        existing = strbuf_detach(&gitdir, NULL);
@@ -59,7 +101,7 @@ char *find_shared_symref(const char *symref, const char *target)
        struct dirent *d;
        char *existing;
 
-       if ((existing = find_linked_symref(symref, target, NULL)))
+       if ((existing = find_main_symref(symref, target)))
                return existing;
 
        strbuf_addf(&path, "%s/worktrees", get_git_common_dir());