diff --git a/maven-model-builder/src/main/java/org/apache/maven/model/merge/MavenModelMerger.java b/maven-model-builder/src/main/java/org/apache/maven/model/merge/MavenModelMerger.java
index a1449ace89..4f4113f986 100644
--- a/maven-model-builder/src/main/java/org/apache/maven/model/merge/MavenModelMerger.java
+++ b/maven-model-builder/src/main/java/org/apache/maven/model/merge/MavenModelMerger.java
@@ -46,6 +46,7 @@ import org.apache.maven.model.Repository;
 import org.apache.maven.model.RepositoryBase;
 import org.apache.maven.model.Scm;
 import org.apache.maven.model.Site;
+import org.codehaus.plexus.util.StringUtils;
 
 /**
  * The domain-specific model merger for the Maven POM, overriding generic code from parent class when necessary with
@@ -443,16 +444,34 @@ public class MavenModelMerger
         if ( src != null )
         {
             Site tgt = target.getSite();
-            if ( sourceDominant || tgt == null )
+            if ( sourceDominant || tgt == null || isSiteEmpty( tgt ) )
             {
-                tgt = new Site();
+                if ( tgt == null )
+                {
+                    tgt = new Site();
+                }
                 tgt.setLocation( "", src.getLocation( "" ) );
                 target.setSite( tgt );
                 mergeSite( tgt, src, sourceDominant, context );
             }
+            mergeSite_ChildSiteUrlInheritAppendPath( tgt, src, sourceDominant, context );
         }
     }
 
+    @Override
+    protected void mergeSite( Site target, Site source, boolean sourceDominant, Map<Object, Object> context )
+    {
+        mergeSite_Id( target, source, sourceDominant, context );
+        mergeSite_Name( target, source, sourceDominant, context );
+        mergeSite_Url( target, source, sourceDominant, context );
+    }
+
+    protected boolean isSiteEmpty( Site site )
+    {
+        return StringUtils.isEmpty( site.getId() ) && StringUtils.isEmpty( site.getName() )
+            && StringUtils.isEmpty( site.getUrl() );
+    }
+
     @Override
     protected void mergeSite_Url( Site target, Site source, boolean sourceDominant, Map<Object, Object> context )
     {
diff --git a/maven-model-builder/src/test/java/org/apache/maven/model/inheritance/DefaultInheritanceAssemblerTest.java b/maven-model-builder/src/test/java/org/apache/maven/model/inheritance/DefaultInheritanceAssemblerTest.java
index b97f37c9d8..07a121ae5e 100644
--- a/maven-model-builder/src/test/java/org/apache/maven/model/inheritance/DefaultInheritanceAssemblerTest.java
+++ b/maven-model-builder/src/test/java/org/apache/maven/model/inheritance/DefaultInheritanceAssemblerTest.java
@@ -103,6 +103,26 @@ public class DefaultInheritanceAssemblerTest
         testInheritance( "no-append-urls" );
     }
 
+    /**
+     * MNG-5951 special case test: inherit with partial override
+     * @throws Exception
+     */
+    public void testNoAppendUrls2()
+        throws Exception
+    {
+        testInheritance( "no-append-urls2" );
+    }
+
+    /**
+     * MNG-5951 special case test: child.x.y.inherit.append.path="true" in child should not reset content
+     * @throws Exception
+     */
+    public void testNoAppendUrls3()
+        throws Exception
+    {
+        testInheritance( "no-append-urls3" );
+    }
+
     /**
      * Tricky case: flat directory structure, but child directory != artifactId.
      * Model interpolation does not give same result when calculated from build or from repo...
diff --git a/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-child.xml b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-child.xml
new file mode 100644
index 0000000000..dbf4dd48d0
--- /dev/null
+++ b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-child.xml
@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>inheritance</groupId>
+    <artifactId>parent</artifactId>
+    <version>11-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>inheritance</artifactId><!-- same as directory name -->
+  <name>Model urls inheritance test child</name>
+
+  <scm>
+    <url>https://domain.org/override</url><!-- check that this won't impact child.site.url.inherit.append.path attribute inheritance -->
+  </scm>
+  <distributionManagement>
+    <site><!-- overriding 1 element will reset all elements, but not child.site.url.inherit.append.path attribute -->
+      <name>reset</name>
+    </site>
+  </distributionManagement>
+</project>
\ No newline at end of file
diff --git a/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-expected.xml b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-expected.xml
new file mode 100644
index 0000000000..4d8e683149
--- /dev/null
+++ b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-expected.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+  child.project.url.inherit.append.path="false">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>inheritance</groupId>
+    <artifactId>parent</artifactId>
+    <version>11-SNAPSHOT</version>
+  </parent>
+
+  <groupId>inheritance</groupId>
+  <artifactId>inheritance</artifactId>
+  <version>11-SNAPSHOT</version>
+  <name>Model urls inheritance test child</name>
+
+  <scm child.scm.connection.inherit.append.path="false"
+       child.scm.developerConnection.inherit.append.path="false"
+       child.scm.url.inherit.append.path="false">
+    <connection>scm:my-scm:http://domain.org/base</connection>
+    <developerConnection>scm:my-scm:https://domain.org/base/</developerConnection>
+    <url>https://domain.org/override</url>
+  </scm>
+  <distributionManagement>
+    <site child.site.url.inherit.append.path="false">
+      <name>reset</name>
+    </site>
+  </distributionManagement>
+</project>
diff --git a/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-parent.xml b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-parent.xml
new file mode 100644
index 0000000000..d2e2e71d78
--- /dev/null
+++ b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls2-parent.xml
@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+  child.project.url.inherit.append.path="false">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>inheritance</groupId>
+  <artifactId>parent</artifactId>
+  <version>11-SNAPSHOT</version>
+
+  <name>Model urls inheritance test parent, with special merge test for mergeSite_ChildSiteUrlInheritAppendPath</name>
+
+  <scm child.scm.connection.inherit.append.path="false"
+       child.scm.developerConnection.inherit.append.path="false"
+       child.scm.url.inherit.append.path="false">
+    <connection>scm:my-scm:http://domain.org/base</connection>
+    <developerConnection>scm:my-scm:https://domain.org/base/</developerConnection>
+    <url>https://domain.org/base</url>
+  </scm>
+  <distributionManagement>
+    <site child.site.url.inherit.append.path="false">
+      <url>scp://scp.domain.org/base/</url>
+    </site>
+  </distributionManagement>
+</project>
\ No newline at end of file
diff --git a/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-child.xml b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-child.xml
new file mode 100644
index 0000000000..ccb2d91747
--- /dev/null
+++ b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-child.xml
@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>inheritance</groupId>
+    <artifactId>parent</artifactId>
+    <version>11-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>inheritance</artifactId><!-- same as directory name -->
+  <name>Model urls inheritance test child</name>
+
+  <scm child.scm.connection.inherit.append.path="true"
+       child.scm.developerConnection.inherit.append.path="true"
+       child.scm.url.inherit.append.path="true" />
+  <distributionManagement>
+    <site child.site.url.inherit.append.path="true" />
+  </distributionManagement>
+</project>
\ No newline at end of file
diff --git a/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-expected.xml b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-expected.xml
new file mode 100644
index 0000000000..a6a884d24e
--- /dev/null
+++ b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-expected.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+  child.project.url.inherit.append.path="false">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>inheritance</groupId>
+    <artifactId>parent</artifactId>
+    <version>11-SNAPSHOT</version>
+  </parent>
+
+  <groupId>inheritance</groupId>
+  <artifactId>inheritance</artifactId>
+  <version>11-SNAPSHOT</version>
+  <name>Model urls inheritance test child</name>
+
+  <scm child.scm.connection.inherit.append.path="true"
+       child.scm.developerConnection.inherit.append.path="true"
+       child.scm.url.inherit.append.path="true">
+    <connection>scm:my-scm:http://domain.org/base</connection>
+    <developerConnection>scm:my-scm:https://domain.org/base/</developerConnection>
+    <url>https://domain.org/base</url>
+  </scm>
+  <distributionManagement>
+    <site child.site.url.inherit.append.path="true">
+      <url>scp://scp.domain.org/base/</url>
+    </site>
+  </distributionManagement>
+</project>
diff --git a/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-parent.xml b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-parent.xml
new file mode 100644
index 0000000000..d2e2e71d78
--- /dev/null
+++ b/maven-model-builder/src/test/resources/poms/inheritance/no-append-urls3-parent.xml
@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+  child.project.url.inherit.append.path="false">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>inheritance</groupId>
+  <artifactId>parent</artifactId>
+  <version>11-SNAPSHOT</version>
+
+  <name>Model urls inheritance test parent, with special merge test for mergeSite_ChildSiteUrlInheritAppendPath</name>
+
+  <scm child.scm.connection.inherit.append.path="false"
+       child.scm.developerConnection.inherit.append.path="false"
+       child.scm.url.inherit.append.path="false">
+    <connection>scm:my-scm:http://domain.org/base</connection>
+    <developerConnection>scm:my-scm:https://domain.org/base/</developerConnection>
+    <url>https://domain.org/base</url>
+  </scm>
+  <distributionManagement>
+    <site child.site.url.inherit.append.path="false">
+      <url>scp://scp.domain.org/base/</url>
+    </site>
+  </distributionManagement>
+</project>
\ No newline at end of file