[API CHANGE] Asserts to never clear already cleared guard

... which could help catch copy-paste errors when wrong guard is cleared
second time.

Also an assert added that when resetting, there's something to reset
(i.e., no descendant class had cleared protected pResetT, making reset
impossible, and thus actually unable to guard anything).

framework/source/layoutmanager/layoutmanager.cxx: made sure to not call
clear() second time

framework/source/layoutmanager/toolbarlayoutmanager.cxx: restored lock
lost in commit 777bc22c

forms/source/misc/InterfaceContainer.cxx: removed a leftover from commit
a19cd21e which reduced guarded scope

forms/source/component/DatabaseForm.cxx: fixed clear-reset sequence
broken from the initial commit bf4154eb

Change-Id: Ibab6660c79561eee31faf3e6c1128ab141a7e8a3
Reviewed-on: https://gerrit.libreoffice.org/70381
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

forms/source/component/DatabaseForm.cxx

@@ -2853,16 +2853,15 @@ void SAL_CALL ODatabaseForm::unload()
             // close the aggregate
             Reference<XCloseable>  xCloseable;
             query_aggregation( m_xAggregate, xCloseable);
-            aGuard.clear();
             if (xCloseable.is())
                 xCloseable->close();
         }
         catch(const SQLException&)
         {
         }
-        aGuard.reset();
     }
 
+    aGuard.reset();
     m_bLoaded = false;
 
     // if the connection we used while we were loaded is only shared with our parent, we

forms/source/misc/InterfaceContainer.cxx

@@ -855,7 +855,6 @@ void OInterfaceContainer::implInsert(sal_Int32 _nIndex, const Reference< XProper
         aEvt.Accessor <<= _nIndex;
         aEvt.Element  = pElementMetaData->aElementTypeInterface;
 
-        aGuard.clear();
         m_aContainerListeners.notifyEach( &XContainerListener::elementInserted, aEvt );
     }
 }

framework/source/layoutmanager/layoutmanager.cxx

@@ -1520,60 +1520,62 @@ void SAL_CALL LayoutManager::destroyElement( const OUString& aName )
 {
     SAL_INFO( "fwk", "framework (cd100003) ::LayoutManager::destroyElement" );
 
+    bool bMustBeLayouted(false);
+    bool bNotify(false);
     /* SAFE AREA ----------------------------------------------------------------------------------------------- */
-    SolarMutexClearableGuard aWriteLock;
+    {
+        SolarMutexClearableGuard aWriteLock;
 
-    bool            bMustBeLayouted( false );
-    bool            bNotify( false );
-    OUString aElementType;
-    OUString aElementName;
+        OUString aElementType;
+        OUString aElementName;
 
-    parseResourceURL( aName, aElementType, aElementName );
+        parseResourceURL(aName, aElementType, aElementName);
 
-    if ( aElementType.equalsIgnoreAsciiCase("menubar") &&
-         aElementName.equalsIgnoreAsciiCase("menubar") )
-    {
-        if ( !m_bInplaceMenuSet )
+        if (aElementType.equalsIgnoreAsciiCase("menubar")
+            && aElementName.equalsIgnoreAsciiCase("menubar"))
         {
-            impl_clearUpMenuBar();
-            m_xMenuBar.clear();
+            if (!m_bInplaceMenuSet)
+            {
+                impl_clearUpMenuBar();
+                m_xMenuBar.clear();
+                bNotify = true;
+            }
+        }
+        else if ((aElementType.equalsIgnoreAsciiCase("statusbar")
+                  && aElementName.equalsIgnoreAsciiCase("statusbar"))
+                 || (m_aStatusBarElement.m_aName == aName))
+        {
+            aWriteLock.clear();
+            implts_destroyStatusBar();
+            bMustBeLayouted = true;
             bNotify = true;
         }
-    }
-    else if (( aElementType.equalsIgnoreAsciiCase("statusbar") &&
-               aElementName.equalsIgnoreAsciiCase("statusbar") ) ||
-             ( m_aStatusBarElement.m_aName == aName ))
-    {
-        aWriteLock.clear();
-        implts_destroyStatusBar();
-        bMustBeLayouted = true;
-        bNotify         = true;
-    }
-    else if ( aElementType.equalsIgnoreAsciiCase("progressbar") &&
-              aElementName.equalsIgnoreAsciiCase("progressbar") )
-    {
-        aWriteLock.clear();
-        implts_createProgressBar();
-        bMustBeLayouted = true;
-        bNotify = true;
-    }
-    else if ( aElementType.equalsIgnoreAsciiCase( UIRESOURCETYPE_TOOLBAR ) && m_xToolbarManager.is() )
-    {
-        aWriteLock.clear();
-        bNotify         = m_xToolbarManager->destroyToolbar( aName );
-        bMustBeLayouted = m_xToolbarManager->isLayoutDirty();
-    }
-    else if ( aElementType.equalsIgnoreAsciiCase("dockingwindow"))
-    {
-        uno::Reference< frame::XFrame > xFrame( m_xFrame );
-        uno::Reference< XComponentContext > xContext( m_xContext );
-        aWriteLock.clear();
+        else if (aElementType.equalsIgnoreAsciiCase("progressbar")
+                 && aElementName.equalsIgnoreAsciiCase("progressbar"))
+        {
+            aWriteLock.clear();
+            implts_createProgressBar();
+            bMustBeLayouted = true;
+            bNotify = true;
+        }
+        else if (aElementType.equalsIgnoreAsciiCase(UIRESOURCETYPE_TOOLBAR)
+                 && m_xToolbarManager.is())
+        {
+            aWriteLock.clear();
+            bNotify = m_xToolbarManager->destroyToolbar(aName);
+            bMustBeLayouted = m_xToolbarManager->isLayoutDirty();
+        }
+        else if (aElementType.equalsIgnoreAsciiCase("dockingwindow"))
+        {
+            uno::Reference<frame::XFrame> xFrame(m_xFrame);
+            uno::Reference<XComponentContext> xContext(m_xContext);
+            aWriteLock.clear();
 
-        impl_setDockingWindowVisibility( xContext, xFrame, aElementName, false );
-        bMustBeLayouted = false;
-        bNotify         = false;
+            impl_setDockingWindowVisibility(xContext, xFrame, aElementName, false);
+            bMustBeLayouted = false;
+            bNotify = false;
+        }
     }
-    aWriteLock.clear();
     /* SAFE AREA ----------------------------------------------------------------------------------------------- */
 
     if ( bMustBeLayouted )

framework/source/layoutmanager/toolbarlayoutmanager.cxx

@@ -440,12 +440,13 @@ bool ToolbarLayoutManager::createToolbar( const OUString& rResourceURL )
 {
     bool bNotify( false );
 
-    SolarMutexClearableGuard aReadLock;
-    uno::Reference< frame::XFrame > xFrame( m_xFrame );
-    uno::Reference< awt::XWindow2 > xContainerWindow( m_xContainerWindow );
-    aReadLock.clear();
-
-    bNotify = false;
+    uno::Reference<frame::XFrame> xFrame;
+    uno::Reference<awt::XWindow2> xContainerWindow;
+    {
+        SolarMutexGuard aReadLock;
+        xFrame.set(m_xFrame);
+        xContainerWindow.set(m_xContainerWindow);
+    }
 
     if ( !xFrame.is() || !xContainerWindow.is() )
         return false;
@@ -457,11 +458,14 @@ bool ToolbarLayoutManager::createToolbar( const OUString& rResourceURL )
 
         uno::Sequence< beans::PropertyValue > aPropSeq( 2 );
         aPropSeq[0].Name = "Frame";
-        aPropSeq[0].Value <<= m_xFrame;
+        aPropSeq[0].Value <<= xFrame;
         aPropSeq[1].Name = "Persistent";
         aPropSeq[1].Value <<= true;
-        uno::Reference< ui::XUIElementFactory > xUIElementFactory( m_xUIElementFactoryManager );
-        aReadLock.clear();
+        uno::Reference<ui::XUIElementFactory> xUIElementFactory;
+        {
+            SolarMutexGuard aReadLock;
+            xUIElementFactory.set(m_xUIElementFactoryManager);
+        }
 
         implts_setToolbarCreation();
         try

include/osl/mutex.hxx

@@ -178,11 +178,9 @@ namespace osl
         */
         void clear()
         {
-            if(pT)
-            {
-                pT->release();
-                pT = NULL;
-            }
+            assert(pT);
+            pT->release();
+            pT = NULL;
         }
     };
 
@@ -216,11 +214,9 @@ namespace osl
         */
         void reset()
         {
-            if( pResetT )
-            {
-                this->pT = pResetT;
-                this->pT->acquire();
-            }
+            assert(!this->pT);
+            this->pT = pResetT;
+            this->pT->acquire();
         }
     };