Update line before Alt+Enter, fix delete_current_line crash (821).

docs/changelog.txt

@@ -105,8 +105,12 @@ USERS
   ending with ? to sometimes fail.
 + Fixed a bug where multichar char tile movement could still
   sometimes jump to the -/+/= chars in the main charset.
-+ Opening the block action menu in the robot editor now updates
-  the contents of the current line.
++ Opening the block action menu in the robot editor (either with
+  Alt+B or Alt+Enter) now updates the current line, fixing bugs
+  where it could copy old line contents to the buffer.
++ Fixed a robot editor crash that could occur when combining two
+  lines with backspace or delete if one of the lines contained
+  the start or end block mark.
 + Fixed a bug in the robot editor where Ctrl+Home and Ctrl+End
   would only set the current line (and not the current column).
 + Fixed a robot editor extended macro crash that would occur:

src/editor/robo_ed.c

@@ -241,10 +241,10 @@ static void delete_current_line(struct robot_editor_context *rstate, int move)
     if(rstate->mark_mode)
     {
       if(rstate->mark_start_rline == current_rline)
-        rstate->mark_start_rline = current_rline->next;
+        rstate->mark_start_rline = next;
 
       if(rstate->mark_end_rline == current_rline)
-        rstate->mark_end_rline = current_rline->previous;
+        rstate->mark_end_rline = previous;
 
       if(rstate->mark_start > rstate->current_line)
         rstate->mark_start--;
@@ -3976,8 +3976,11 @@ static boolean robot_editor_key(context *ctx, int *key)
 
     case IKEY_RETURN:
     {
+      // Block action menu (also see Alt+B).
       if(get_alt_status(keycode_internal))
       {
+        end_intake_undo_frame(rstate);
+        update_current_line(rstate, true);
         block_action(rstate);
       }
       else
@@ -4293,7 +4296,7 @@ static boolean robot_editor_key(context *ctx, int *key)
       break;
     }
 
-    // Block action menu
+    // Block action menu (also see Alt+Enter).
     case IKEY_b:
     {
       if(get_alt_status(keycode_internal))