[locale] Test the TZ image loader

- QImage needs Qt5::Gui, so this isn't a guiless-test; it can use
  the offscreen QPA, though.
- Check that the images are all the same size
- Debugging / check code removed from timezonewidget

src/modules/locale/CMakeLists.txt

@@ -37,4 +37,9 @@ calamares_add_test(
     SOURCES
         Tests.cpp
         LocaleConfiguration.cpp
+        timezonewidget/TimeZoneImage.cpp
+    DEFINITIONS
+        SOURCE_DIR="${CMAKE_CURRENT_LIST_DIR}/images"
+    LIBRARIES
+        Qt5::Gui
 )

src/modules/locale/Tests.cpp

@@ -19,12 +19,13 @@
 
 #include "Tests.h"
 #include "LocaleConfiguration.h"
+#include "timezonewidget/TimeZoneImage.h"
 
 #include "locale/TimeZone.h"
 
 #include <QtTest/QtTest>
 
-QTEST_GUILESS_MAIN( LocaleTests )
+QTEST_MAIN( LocaleTests )
 
 
 LocaleTests::LocaleTests() {}
@@ -84,6 +85,31 @@ void
 LocaleTests::testTZImages()
 {
     Logger::setupLogLevel( Logger::LOGDEBUG );
+
+    // Number of zone images
+    //
+    //
+    auto images = TimeZoneImageList::fromDirectory( SOURCE_DIR );
+    QCOMPARE( images.count(), images.zoneCount() );
+    QCOMPARE( images.count(), 38 );  // counted by hand
+
+    // All image sizes consistent
+    //
+    //
+    const QSize windowSize( 780, 340 );
+    {
+        QImage background( SOURCE_DIR "/bg.png" );
+        QVERIFY( !background.isNull() );
+        QCOMPARE( background.size(), windowSize );
+    }
+    for ( const auto& image : images )
+    {
+        QCOMPARE( image.size(), windowSize );
+    }
+
+    // Check zones are uniquely-claimed
+    //
+    //
     using namespace CalamaresUtils::Locale;
     const CStringPairList& regions = TZRegion::fromZoneTab();
 

src/modules/locale/timezonewidget/timezonewidget.cpp

@@ -55,13 +55,6 @@ TimeZoneWidget::TimeZoneWidget( QWidget* parent )
     background = QImage( ":/images/bg.png" );
     pin = QImage( ":/images/pin.png" );
 
-#ifdef DEBUG_TIMEZONES
-    if ( background.size() != QSize( 780, 340 ) )
-    {
-        cWarning() << "Timezone background size mismatch" << background.size();
-    }
-#endif
-
     // Set size
     setMinimumSize( background.size() );
     setMaximumSize( background.size() );