Correctly handle crs restoration after an invalid crs was written to xml

qgis · May 24, 2019 · 8350ad6 · 8350ad6
1 parent e49b07c
commit 8350ad6
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Showing 2 changed files with 21 additions and 7 deletions.
diff --git a/src/core/qgscoordinatereferencesystem.cpp b/src/core/qgscoordinatereferencesystem.cpp
@@ -1655,11 +1655,12 @@ bool QgsCoordinateReferenceSystem::readXml( const QDomNode &node )
   {
     bool initialized = false;
 
-    long srsid = srsNode.namedItem( QStringLiteral( "srsid" ) ).toElement().text().toLong();
+    bool ok = false;
+    long srsid = srsNode.namedItem( QStringLiteral( "srsid" ) ).toElement().text().toLong( &ok );
 
     QDomNode myNode;
 
-    if ( srsid < USER_CRS_START_ID )
+    if ( ok && srsid > 0 && srsid < USER_CRS_START_ID )
     {
       myNode = srsNode.namedItem( QStringLiteral( "authid" ) );
       if ( !myNode.isNull() )
@@ -1688,13 +1689,13 @@ bool QgsCoordinateReferenceSystem::readXml( const QDomNode &node )
     if ( !initialized )
     {
       myNode = srsNode.namedItem( QStringLiteral( "proj4" ) );
+      const QString proj4 = myNode.toElement().text();
 
-      if ( !createFromProj4( myNode.toElement().text() ) )
+      if ( !createFromProj4( proj4 ) )
       {
         // Setting from elements one by one
-
-        myNode = srsNode.namedItem( QStringLiteral( "proj4" ) );
-        setProj4String( myNode.toElement().text() );
+        if ( !proj4.trimmed().isEmpty() )
+          setProj4String( myNode.toElement().text() );
 
         myNode = srsNode.namedItem( QStringLiteral( "srsid" ) );
         setInternalId( myNode.toElement().text().toLong() );
@@ -1731,7 +1732,7 @@ bool QgsCoordinateReferenceSystem::readXml( const QDomNode &node )
       // this behavior was changed in order to separate creation and saving.
       // Not sure if it necessary to save it here, should be checked by someone
       // familiar with the code (should also give a more descriptive name to the generated CRS)
-      if ( d->mSrsId == 0 )
+      if ( isValid() && d->mSrsId == 0 )
       {
         QString myName = QStringLiteral( " * %1 (%2)" )
                          .arg( QObject::tr( "Generated CRS", "A CRS automatically generated from layer info get this prefix for description" ),

diff --git a/tests/src/core/testqgscoordinatereferencesystem.cpp b/tests/src/core/testqgscoordinatereferencesystem.cpp
@@ -634,6 +634,19 @@ void TestQgsCoordinateReferenceSystem::readWriteXml()
   QDomDocument document( "test" );
   QDomElement node = document.createElement( QStringLiteral( "crs" ) );
   document.appendChild( node );
+
+  // start with invalid node
+  QgsCoordinateReferenceSystem badCrs;
+  QVERIFY( !badCrs.readXml( node ) );
+  QVERIFY( !badCrs.isValid() );
+  QDomElement badSrsElement  = document.createElement( QStringLiteral( "spatialrefsys" ) );
+  QDomElement badNode = document.createElement( QStringLiteral( "crs" ) );
+  document.appendChild( badNode );
+  badNode.appendChild( badSrsElement );
+  // should return true, because it's ok to write/read invalid crs to xml
+  QVERIFY( badCrs.readXml( badNode ) );
+  QVERIFY( !badCrs.isValid() );
+
   QVERIFY( myCrs.writeXml( node, document ) );
   QgsCoordinateReferenceSystem myCrs2;
   QVERIFY( myCrs2.readXml( node ) );