(Fmarker_buffer): Make test for odd case into a failure.

1 files changed, 6 insertions, 3 deletions

diff --git a/src/marker.c b/src/marker.c
index a57dafa3f3b..0c89f71d79a 100644
--- a/src/marker.c
+++ b/src/marker.c
@@ -452,9 +452,12 @@ Returns nil if MARKER points into a dead buffer.  */)
   if (XMARKER (marker)->buffer)
     {
       XSETBUFFER (buf, XMARKER (marker)->buffer);
-      /* Return marker's buffer only if it is not dead.  */
-      if (!NILP (XBUFFER (buf)->name))
-        return buf;
+      /* If the buffer is dead, we're in trouble: the buffer pointer here
+         does not preserve the buffer from being GC'd (it's weak), so
+         markers have to be unlinked from their buffer as soon as the buffer
+         is killed.  */
+      eassert (!NILP (XBUFFER (buf)->name));
+      return buf;
     }
   return Qnil;
 }