Sidebar: Show default line-color in 'Draw'

Currently, the default color shown in Sidebar>Line>Color
is yellow and is not updated until and unless one hovers a
mouse on top of it. This is wrong and the default color of
the line-color should be updated and shown by default.

Change-Id: I213cba84a0fc726220acfe547955a96d6bb4446b
Reviewed-on: https://gerrit.libreoffice.org/5932Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

svx/source/sidebar/line/LinePropertyPanel.cxx

@@ -337,6 +337,9 @@ void LinePropertyPanel::NotifyItemUpdate(
     (void)bIsEnabled;
     const bool bDisabled(SFX_ITEM_DISABLED == eState);
 
+    // By default, fill and show the color of existing line-color
+    mpColorUpdater->Update( maColor );
+
     switch(nSID)
     {
         case SID_ATTR_LINE_COLOR:
@@ -359,7 +362,7 @@ void LinePropertyPanel::NotifyItemUpdate(
                 {
                     maColor = pItem->GetColorValue();
                     mbColorAvailable = true;
-                    mpColorUpdater->Update(maColor);
+                    mpColorUpdater->Update( maColor );
                     break;
                 }
             }

svx/source/tbxctrls/tbxcolorupdate.cxx

@@ -92,7 +92,11 @@ namespace svx
         if( aColor.GetColor() == COL_AUTO )
             aColor = Color( COL_TRANSPARENT );
 
-        if( ( maCurColor != aColor ) || bSizeChanged || bDisplayModeChanged )
+        // For a shape selected in 'Draw', when color selected in Sidebar > Line > Color
+        // is COL_BLACK, then (maCurColor != aColor) becomes 'false', therefore we take
+        // explicit care of COL_BLACK from the last argument in the condition so that the
+        // Update() does its routine job appropriately !
+        if( ( maCurColor != aColor ) || bSizeChanged || bDisplayModeChanged || ( aColor == COL_BLACK ) )
         {
             // create an empty bitmap, and copy the original bitmap inside
             // (so that it grows in case the original bitmap was smaller)