Merge pull request #9723 from qgis/backport-9696-to-release-3_4

[Backport release-3_4] [server] Server removes empty string in style parameter even if it describes default style

python/server/auto_generated/qgsserverparameters.sip.in

@@ -48,11 +48,12 @@ Returns true if the parameter is valid, false otherwise.
 Converts the parameter into a string.
 %End
 
-    QStringList toStringList( char delimiter = ',' ) const;
+    QStringList toStringList( char delimiter = ',', bool skipEmptyParts = true ) const;
 %Docstring
-Converts the parameter into a list of strings.
+Converts the parameter into a list of strings
 
 :param delimiter: The character used for delimiting
+:param skipEmptyParts: To use QString.SkipEmptyParts for splitting
 
 :return: A list of strings
 %End

src/server/qgsserverparameters.cpp

@@ -66,9 +66,21 @@ QString QgsServerParameterDefinition::toString() const
   return mValue.toString();
 }
 
-QStringList QgsServerParameterDefinition::toStringList( const char delimiter ) const
+QStringList QgsServerParameterDefinition::toStringList( const char delimiter, const bool skipEmptyParts ) const
 {
-  return toString().split( delimiter, QString::SkipEmptyParts );
+  if ( skipEmptyParts )
+  {
+    return toString().split( delimiter, QString::SkipEmptyParts );
+  }
+  else
+  {
+    QStringList list;
+    if ( !toString().isEmpty() )
+    {
+      list = toString().split( delimiter, QString::KeepEmptyParts );
+    }
+    return list;
+  }
 }
 
 QList<QgsGeometry> QgsServerParameterDefinition::toGeomList( bool &ok, const char delimiter ) const

src/server/qgsserverparameters.h

@@ -65,11 +65,12 @@ class SERVER_EXPORT QgsServerParameterDefinition
     QString toString() const;
 
     /**
-     * Converts the parameter into a list of strings.
+     * Converts the parameter into a list of strings
      * \param delimiter The character used for delimiting
+     * \param skipEmptyParts To use QString::SkipEmptyParts for splitting
      * \returns A list of strings
      */
-    QStringList toStringList( char delimiter = ',' ) const;
+    QStringList toStringList( char delimiter = ',', bool skipEmptyParts = true ) const;
 
     /**
      * Converts the parameter into a list of integers.

src/server/services/wms/qgswmsparameters.cpp

@@ -45,6 +45,11 @@ namespace QgsWms
     QgsServerParameterDefinition::raiseError( msg );
   }
 
+  QStringList QgsWmsParameter::toStyleList( const char delimiter ) const
+  {
+    return QgsServerParameterDefinition::toStringList( delimiter, false );
+  }
+
   QList<QgsGeometry> QgsWmsParameter::toGeomList( const char delimiter ) const
   {
     bool ok = true;
@@ -1287,8 +1292,8 @@ namespace QgsWms
 
   QStringList QgsWmsParameters::allStyles() const
   {
-    QStringList style = mWmsParameters[ QgsWmsParameter::STYLE ].toStringList();
-    const QStringList styles = mWmsParameters[ QgsWmsParameter::STYLES ].toStringList();
+    QStringList style = mWmsParameters[ QgsWmsParameter::STYLE ].toStyleList();
+    const QStringList styles = mWmsParameters[ QgsWmsParameter::STYLES ].toStyleList();
     return style << styles;
   }
 
@@ -1550,7 +1555,7 @@ namespace QgsWms
     wmsParam = idParameter( QgsWmsParameter::STYLES, mapId );
     if ( wmsParam.isValid() )
     {
-      styles = wmsParam.toStringList();
+      styles = wmsParam.toStyleList();
     }
 
     QList<QgsWmsParametersLayer> lParams;

src/server/services/wms/qgswmsparameters.h

@@ -192,6 +192,15 @@ namespace QgsWms
        */
       bool isValid() const override;
 
+      /**
+       * Converts the parameter into a list of strings and keeps empty parts
+       * Default style value is an empty string
+       * \param delimiter The character used for delimiting
+       * \returns A list of strings
+       * \since QGIS 3.8
+       */
+      QStringList toStyleList( const char delimiter = ',' ) const;
+
       /**
        * Converts the parameter into a list of geometries.
        * \param delimiter The character delimiting string geometries

tests/src/python/test_qgsserver_wms_getmap.py

@@ -723,6 +723,58 @@ def test_wms_getmap_style(self):
         r, h = self._result(self._execute_request(qs))
         self._img_diff_error(r, h, "WMS_GetMap_StyleCustom")
 
+        # mixed custom and default style with STYLES parameter
+        qs = "?" + "&".join(["%s=%s" % i for i in list({
+            "MAP": urllib.parse.quote(self.projectPath),
+            "SERVICE": "WMS",
+            "VERSION": "1.1.1",
+            "REQUEST": "GetMap",
+            "LAYERS": "Country_Labels,Hello",
+            "STYLES": "custom,",
+            "FORMAT": "image/png",
+            "BBOX": "-16817707,-4710778,5696513,14587125",
+            "HEIGHT": "500",
+            "WIDTH": "500",
+            "CRS": "EPSG:3857"
+        }.items())])
+
+        r, h = self._result(self._execute_request(qs))
+        self._img_diff_error(r, h, "WMS_GetMap_StyleMixed")
+
+        qs = "?" + "&".join(["%s=%s" % i for i in list({
+            "MAP": urllib.parse.quote(self.projectPath),
+            "SERVICE": "WMS",
+            "VERSION": "1.1.1",
+            "REQUEST": "GetMap",
+            "LAYERS": "Hello,Country_Labels",
+            "STYLES": "default,custom",
+            "FORMAT": "image/png",
+            "BBOX": "-16817707,-4710778,5696513,14587125",
+            "HEIGHT": "500",
+            "WIDTH": "500",
+            "CRS": "EPSG:3857"
+        }.items())])
+
+        r, h = self._result(self._execute_request(qs))
+        self._img_diff_error(r, h, "WMS_GetMap_StyleMixed_LayerOrder")
+
+        qs = "?" + "&".join(["%s=%s" % i for i in list({
+            "MAP": urllib.parse.quote(self.projectPath),
+            "SERVICE": "WMS",
+            "VERSION": "1.1.1",
+            "REQUEST": "GetMap",
+            "LAYERS": "Hello,Country_Labels",
+            "STYLES": ",custom",
+            "FORMAT": "image/png",
+            "BBOX": "-16817707,-4710778,5696513,14587125",
+            "HEIGHT": "500",
+            "WIDTH": "500",
+            "CRS": "EPSG:3857"
+        }.items())])
+
+        r, h = self._result(self._execute_request(qs))
+        self._img_diff_error(r, h, "WMS_GetMap_StyleMixed_LayerOrder")
+
     def test_wms_getmap_filter(self):
         qs = "?" + "&".join(["%s=%s" % i for i in list({
             "MAP": urllib.parse.quote(self.projectPath),