From c70526841e86bf72d0714db84305cd35ac62f527 Mon Sep 17 00:00:00 2001
From: Sinny Kumari <sinny@redhat.com>
Date: Thu, 4 Oct 2018 19:18:05 +0530
Subject: [PATCH] src/ostree: Don't delete refs having aliases

Deleting a ref with aliases makes them dangling. In such
cases, display an error message to the user.

Fixes #1597

Signed-off-by: Sinny Kumari <sinny@redhat.com>

Closes: #1749
Approved by: cgwalters
---
 src/ostree/ot-builtin-refs.c | 17 +++++++++++++++--
 tests/test-refs.sh           |  5 +++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/ostree/ot-builtin-refs.c b/src/ostree/ot-builtin-refs.c
index 5c2214cc..f88d08a6 100644
--- a/src/ostree/ot-builtin-refs.c
+++ b/src/ostree/ot-builtin-refs.c
@@ -146,8 +146,10 @@ static gboolean do_ref (OstreeRepo *repo, const char *refspec_prefix, GCancellab
 
   /* If we're doing aliasing, we need the full list of aliases mostly to allow
    * replacing existing aliases.
+   * If we are deleting a ref, we want to make sure that it doesn't have
+   * any corresponding aliases.
    */
-  if (opt_alias)
+  if (opt_alias || opt_delete)
     {
       if (!ostree_repo_list_refs_ext (repo, NULL, &ref_aliases,
                                       OSTREE_REPO_LIST_REFS_EXT_ALIASES,
@@ -245,7 +247,18 @@ static gboolean do_ref (OstreeRepo *repo, const char *refspec_prefix, GCancellab
 
           if (!ostree_parse_refspec (refspec, &remote, &ref, error))
             goto out;
-          
+
+          /* Look for alias if it exists for a ref we want to delete */
+          GLNX_HASH_TABLE_FOREACH_KV (ref_aliases, const char *,
+                                      ref_alias, const char *, value)
+            {
+              if (!strcmp (ref, value))
+                {
+                  g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                               "Ref '%s' has an active alias: '%s'", ref, ref_alias);
+                  goto out;
+                }
+            }
           if (!ostree_repo_set_ref_immediate (repo, remote, ref, NULL,
                                               cancellable, error))
             goto out;
diff --git a/tests/test-refs.sh b/tests/test-refs.sh
index f4fe1833..1730423d 100755
--- a/tests/test-refs.sh
+++ b/tests/test-refs.sh
@@ -192,6 +192,11 @@ done
 ${CMD_PREFIX} ostree --repo=repo refs -A > refs.txt
 assert_file_has_content_literal refs.txt 'exampleos/x86_64/stable/server -> exampleos/x86_64/27/server'
 
+# Test that we don't delete a ref having aliases
+if ${CMD_PREFIX} ostree --repo=repo refs --delete exampleos/x86_64/27/server; then
+    assert_not_reached "refs --delete unexpectedly succeeded in deleting a ref containing alias!"
+fi
+
 ${CMD_PREFIX} ostree --repo=repo summary -u
 
 echo "ok ref symlink"