Don't lose track of the current message when collapsing and changing

sort modes wildly.  Noted by David T-G.

2 files changed, 11 insertions, 2 deletions

diff --git a/curs_main.c b/curs_main.c
index 8baefbc2..07b82cbf 100644
--- a/curs_main.c
+++ b/curs_main.c
@@ -363,10 +363,12 @@ static void update_index (MUTTMENU *menu, CONTEXT *ctx, int check,
 static void resort_index (MUTTMENU *menu)
 {
   int i;
-  const HEADER *current = CURHDR;
+  HEADER *current = CURHDR;
 
+  menu->current = -1;
   mutt_sort_headers (Context, 0);
   /* Restore the current message */
+
   for (i = 0; i < Context->vcount; i++)
   {
     if (Context->hdrs[Context->v2r[i]] == current)
@@ -375,6 +377,13 @@ static void resort_index (MUTTMENU *menu)
       break;
     }
   }
+  
+  if ((Sort & SORT_MASK) == SORT_THREADS && menu->current < 0)
+    menu->current = mutt_parent_message (Context, current);
+  
+  if (menu->current < 0)
+    menu->current = ci_first_message ();
+  
   menu->redraw = REDRAW_INDEX | REDRAW_STATUS;
 }
 
diff --git a/thread.c b/thread.c
index a071e90e..a729baeb 100644
--- a/thread.c
+++ b/thread.c
@@ -756,7 +756,7 @@ int mutt_parent_message (CONTEXT *ctx, HEADER *hdr)
   {
     while ((hdr = hdr->parent))
     {
-      if (!ctx->pattern || hdr->limited)
+      if (hdr->virtual >= 0 && hdr->collapsed && (!ctx->pattern || hdr->limited))
 	return (hdr->virtual);
     }
     mutt_error _("Parent message is not visible in limited view");