Check for hidden dirty child on close

Fixes: #11405

diff --git a/src/frontends/qt4/GuiView.cpp b/src/frontends/qt4/GuiView.cpp
index 56f4f7b4c6d2119af50e1ae7b30d8a94b1a9ba10..9d5f5dca6a43a98b726d6062bb4466324085bf0a 100644 (file)
--- a/src/frontends/qt4/GuiView.cpp
+++ b/src/frontends/qt4/GuiView.cpp
@@ -3069,9 +3069,13 @@ bool GuiView::closeBuffer(Buffer & buf)
                                        break;
                        } else {
                                // In this case the child buffer is open but hidden.
-                               // It therefore should not (MUST NOT) be dirty!
-                               LATTEST(child_buf->isClean());
-                               theBufferList().release(child_buf);
+                               // Even in this case, children can be dirty (e.g.,
+                               // after a label change in the master, see #11405).
+                               // Therefore, check this.
+                               if (saveBufferIfNeeded(*child_buf, false)) {
+                                       child_buf->removeAutosaveFile();
+                                       theBufferList().release(child_buf);
+                               }
                        }
                }
        }