Warn when trying to load an icon without a matching icon engine

A typical case is trying to load an SVG icon without the QtSvg module
built. You want to know what's going on instead of trying to debug why
the icon doesn't produce any valid images.

Change-Id: I4418ad758a1232f1394058368c50e0d87235271e
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index 41fe649fc5..562e5e9a3e 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -1049,6 +1049,8 @@ static QIconEngine *iconEngineFromSuffix(const QString &fileName, const QString
             }
         }
     }
+    qWarning("Could not find icon engine for suffix '%s' of file '%s'",
+        qUtf8Printable(suffix), qUtf8Printable(fileName));
     return nullptr;
 }