[ogr] Rename columns with non-unique name (Fix #8385)

Author: m-kuhn

src/providers/ogr/qgsogrprovider.cpp

@@ -670,14 +670,28 @@ void QgsOgrProvider::loadFields()
         default: varType = QVariant::String; // other unsupported, leave it as a string
       }
 
-      mAttributeFields.append(
-        QgsField(
-          //TODO: fix this hack
+      //TODO: fix this hack
 #ifdef ANDROID
-          OGR_Fld_GetNameRef( fldDef ),
+      QString name = OGR_Fld_GetNameRef( fldDef );
 #else
-          mEncoding->toUnicode( OGR_Fld_GetNameRef( fldDef ) ),
+      QString name = mEncoding->toUnicode( OGR_Fld_GetNameRef( fldDef ) );
 #endif
+
+      if ( mAttributeFields.indexFromName( name ) != -1 )
+      {
+
+        QString tmpname = name + "_%1";
+        int fix = 0;
+
+        while ( mAttributeFields.indexFromName( name ) != -1 )
+        {
+          name = tmpname.arg( ++fix );
+        }
+      }
+
+      mAttributeFields.append(
+        QgsField(
+          name,
           varType,
 #ifdef ANDROID
           OGR_GetFieldTypeName( ogrType ),