QgsSvgCache::svgAsPicture(): make sure the returned picture is not shared (fixes #18996)

rouault · rouault · commit 75b7edf1d211 · 2018-06-01T22:00:07.000+02:00
For some reason QPicture.detach() doesn't seem to always work as intended, at least with QT 5.5 on Ubuntu 16.04 Serialization/deserialization is a safe way to be ensured we don't share a copy. Relates to a6eea72
diff --git a/src/core/symbology/qgssvgcache.cpp b/src/core/symbology/qgssvgcache.cpp
@@ -182,8 +182,12 @@ QPicture QgsSvgCache::svgAsPicture( const QString &path, double size, const QCol
     trimToMaximumSize();
   }
 
-  QPicture p = *( currentEntry->picture );
-  p.detach();
+  QPicture p;
+  // For some reason p.detach() doesn't seem to always work as intended, at
+  // least with QT 5.5 on Ubuntu 16.04
+  // Serialization/deserialization is a safe way to be ensured we don't
+  // share a copy.
+  p.setData( currentEntry->picture->data(), currentEntry->picture->size() );
   return p;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -182,8 +182,12 @@ QPicture QgsSvgCache::svgAsPicture( const QString &path, double size, const QCol`
`182`	`182`	`trimToMaximumSize();`
`183`	`183`	`}`
`184`	`184`
`185`		`- QPicture p = *( currentEntry->picture );`
`186`		`- p.detach();`
	`185`	`+ QPicture p;`
	`186`	`+ // For some reason p.detach() doesn't seem to always work as intended, at`
	`187`	`+ // least with QT 5.5 on Ubuntu 16.04`
	`188`	`+ // Serialization/deserialization is a safe way to be ensured we don't`
	`189`	`+ // share a copy.`
	`190`	`+ p.setData( currentEntry->picture->data(), currentEntry->picture->size() );`
`187`	`191`	`return p;`
`188`	`192`	`}`
`189`	`193`