[LyX/master] Fix for bug #11974

[Stephan Witt]

commit 96a4dd235eae438073b3a2b00c73ff930f7be14a
Author: Daniel Ramoeller <d.lyx at web.de>
Date:   Tue Sep 15 07:31:53 2020 +0200

    Fix for bug #11974
    
    Support for setUnifiedTitleAndToolBarOnMac (unify toolbar and title bar).
---
 src/frontends/qt/GuiView.cpp |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/frontends/qt/GuiView.cpp b/src/frontends/qt/GuiView.cpp
index 767791f..9aa325f 100644
--- a/src/frontends/qt/GuiView.cpp
+++ b/src/frontends/qt/GuiView.cpp
@@ -1039,6 +1039,11 @@ void GuiView::updateLockToolbars()
 		if (tb && tb->isMovable())
 			toolbarsMovable_ = true;
 	}
+#if QT_VERSION >= 0x050200
+	// set unified mac toolbars only when not movable as recommended:
+	// https://doc.qt.io/qt-5/qmainwindow.html#unifiedTitleAndToolBarOnMac-prop
+	setUnifiedTitleAndToolBarOnMac(!toolbarsMovable_);
+#endif
 }
 
 
@@ -4488,12 +4493,11 @@ void GuiView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 					dr.setMessage(_("Toolbars unlocked."));
 				else
 					dr.setMessage(_("Toolbars locked."));
-			} else if (GuiToolbar * t = toolbar(name)) {
+			} else if (GuiToolbar * tb = toolbar(name))
 				// toggle current toolbar movablity
-				t->movable();
-				// update lock (all) toolbars positions
-				updateLockToolbars();
-			}
+				tb->movable();
+			// update lock (all) toolbars positions
+			updateLockToolbars();
 			break;
 		}