[categorized] Fix blank layers when using categorized renderer

nyalldawson · nyalldawson · commit 7714bfbfbe6a · 2019-02-12T13:37:55.000+10:00
Fixes #21188
diff --git a/src/core/symbology/qgscategorizedsymbolrenderer.cpp b/src/core/symbology/qgscategorizedsymbolrenderer.cpp
@@ -533,7 +533,7 @@ QString QgsCategorizedSymbolRenderer::filter( const QgsFields &fields )
 
   for ( const QgsRendererCategory &cat : qgis::as_const( mCategories ) )
   {
-    if ( cat.value() == "" )
+    if ( cat.value() == "" || cat.value().isNull() )
     {
       hasDefault = true;
       defaultActive = cat.renderState();

Original file line number	Diff line number	Diff line change
`@@ -533,7 +533,7 @@ QString QgsCategorizedSymbolRenderer::filter( const QgsFields &fields )`
`533`	`533`
`534`	`534`	`for ( const QgsRendererCategory &cat : qgis::as_const( mCategories ) )`
`535`	`535`	`{`
`536`		`- if ( cat.value() == "" )`
	`536`	`+ if ( cat.value() == "" \|\| cat.value().isNull() )`
`537`	`537`	`{`
`538`	`538`	`hasDefault = true;`
`539`	`539`	`defaultActive = cat.renderState();`