[mdoc] `multiassembly` option for duplicated types

The new `multiassembly` option lets you run `mdoc update` on assemblies that
contain the same types. This can come into play when you have a set of assemblies
that run on different platforms, with a slightly differing API surface area on
each platform (for example: tvOS, watchOS, iOS); in this case you can maintain
all of the documentation in a single set of XML documents.

With this option enabled, an `AssemblyInfo` node will be added for every assembly
that a type is found in, in addition to every member. While this may seem verbose,
it's really the only way to capture the information about what assemblies a given
type or member can be found in.

8 files changed, 336 insertions, 26 deletions

diff --git a/mdoc/Makefile b/mdoc/Makefile
index 0991269d..26e60874 100644
--- a/mdoc/Makefile
+++ b/mdoc/Makefile
@@ -60,6 +60,9 @@ EXTRA_DISTFILES = \
 	$(MDOC_RESOURCES) \
 	$(MDOC_TEST_FILES)
 
+MULTI-CLASSIC = Test/DocTest-DropNS-classic.dll Test/DocTest-DropNS-classic-multitest.dll
+MULTI-UNIFIED = Test/DocTest-DropNS-unified.dll Test/DocTest-DropNS-unified-multitest.dll
+
 $(PROGRAM) : $(MDOC_RESOURCES) $(MONODOC_RESOURCES) $(PROGRAM_DEPS)
 
 PROGRAM_COMPILE = $(CSCOMPILE) -platform:x86
@@ -108,6 +111,14 @@ Test/DocTest-DropNS-classic.dll:
 Test/DocTest-DropNS-unified.dll:
 	$(CSCOMPILE) $(TEST_CSCFLAGS) -debug -unsafe -target:library -out:$@ Test/DocTest-DropNS-unified.cs
 
+Test/DocTest-DropNS-unified-multitest.dll:
+	rm -f $@
+	$(CSCOMPILE) $(TEST_CSCFLAGS) -debug -unsafe -target:library -out:$@ Test/DocTest-DropNS-unified.cs /define:MULTITEST
+
+Test/DocTest-DropNS-classic-multitest.dll:
+	rm -f $@
+	$(CSCOMPILE) $(TEST_CSCFLAGS) -debug -unsafe -target:library -out:$@ Test/DocTest-DropNS-classic.cs /define:MULTITEST
+
 Test/DocTest-DropNS-unified-deletetest.dll:
 	rm -f Test/DocTest-DropNS-unified-deletetest.dll
 	$(CSCOMPILE) $(TEST_CSCFLAGS) -debug -unsafe -target:library -out:$@ Test/DocTest-DropNS-unified.cs /define:DELETETEST
@@ -167,6 +178,23 @@ check-monodocer-dropns-classic: $(PROGRAM)
 	$(MAKE) update-monodocer-dropns-unified
 	diff --exclude=.svn -rup Test/en.expected-dropns-classic-v1 Test/en.actual
 
+check-monodocer-dropns-multi: $(PROGRAM)
+	-rm -Rf Test/en.actual
+	$(MAKE) Test/DocTest-DropNS-classic.dll
+	$(MAKE) Test/DocTest-DropNS-unified.dll
+	$(MAKE) Test/DocTest-DropNS-classic-multitest.dll
+	$(MAKE) Test/DocTest-DropNS-unified-multitest.dll
+
+	# mdoc update for both classic and unified
+	$(MONO) $(PROGRAM) update --exceptions=all -o Test/en.actual $(MULTI-CLASSIC) -multiassembly
+	$(MONO) $(PROGRAM) update --exceptions=all -o Test/en.actual $(MULTI-UNIFIED) --dropns Test/DocTest-DropNS-unified.dll=MyFramework --dropns Test/DocTest-DropNS-unified-multitest.dll=MyFramework -multiassembly
+	
+	# now run it again to verify idempotency
+	$(MONO) $(PROGRAM) update --exceptions=all -o Test/en.actual $(MULTI-CLASSIC) -multiassembly
+	$(MONO) $(PROGRAM) update --exceptions=all -o Test/en.actual $(MULTI-UNIFIED) --dropns Test/DocTest-DropNS-unified.dll=MyFramework --dropns Test/DocTest-DropNS-unified-multitest.dll=MyFramework -multiassembly
+	
+	diff --exclude=.svn -rup Test/en.expected-dropns-multi Test/en.actual
+
 check-monodocer-dropns-delete: $(PROGRAM)
 	-rm -Rf Test/en.actual
 	rm -Rf Test/DocTest-DropNS-classic-deletetest.dll
@@ -370,7 +398,8 @@ check-doc-tools: check-monodocer-since \
 	check-monodocer-dropns-classic-withsecondary \
 	check-monodocer-dropns-delete \
 	check-monodocer-internal-interface \
-	check-monodocer-enumerations
+	check-monodocer-enumerations \
+	check-monodocer-dropns-multi
 
 check-doc-tools-update: check-monodocer-since-update \
 	check-monodocer-importecmadoc-update \
diff --git a/mdoc/Mono.Documentation/monodocer.cs b/mdoc/Mono.Documentation/monodocer.cs
index 7d54a289..a1f91f3b 100644
--- a/mdoc/Mono.Documentation/monodocer.cs
+++ b/mdoc/Mono.Documentation/monodocer.cs
@@ -133,6 +133,7 @@ class MDocUpdater : MDocCommand
 	List<AssemblyDefinition> assemblies;
 	readonly DefaultAssemblyResolver assemblyResolver = new DefaultAssemblyResolver();
 	
+	bool multiassembly;
 	bool delete;
 	bool show_exceptions;
 	bool no_assembly_versions, ignore_missing_types;
@@ -278,6 +279,9 @@ class MDocUpdater : MDocCommand
 			{ "preserve",
 				"Do not delete members that don't exist in the assembly, but rather mark them as preserved.",
 				v => PreserveTag = "true" },
+			{ "multiassembly",
+				"Allow types to be in multiple assemblies.",
+				v => multiassembly = true },
 		};
 		var assemblies = Parse (p, args, "update", 
 				"[OPTIONS]+ ASSEMBLIES",
@@ -767,7 +771,13 @@ class MDocUpdater : MDocCommand
 
 	private void AddIndexAssembly (AssemblyDefinition assembly, XmlElement parent)
 	{
-		XmlElement index_assembly = parent.OwnerDocument.CreateElement("Assembly");
+		XmlElement index_assembly = null;
+		if (multiassembly) 
+			index_assembly = (XmlElement)parent.SelectSingleNode ("Assembly[@Name='"+ assembly.Name.Name +"']");
+		
+		if (index_assembly == null) 
+			index_assembly = parent.OwnerDocument.CreateElement ("Assembly");
+
 		index_assembly.SetAttribute ("Name", assembly.Name.Name);
 		index_assembly.SetAttribute ("Version", assembly.Name.Version.ToString());
 
@@ -842,7 +852,8 @@ class MDocUpdater : MDocCommand
 		
 		XmlElement index_types = WriteElement(index.DocumentElement, "Types");
 		XmlElement index_assemblies = WriteElement(index.DocumentElement, "Assemblies");
-		index_assemblies.RemoveAll ();
+		if (!multiassembly) 
+			index_assemblies.RemoveAll ();
 
 
 		HashSet<string> goodfiles = new HashSet<string> (StringComparer.OrdinalIgnoreCase);
@@ -1535,28 +1546,15 @@ class MDocUpdater : MDocCommand
 				type);
 		}
 		
-		string assemblyInfoNodeFilter = MDocUpdater.HasDroppedNamespace (type) ? "[@apistyle='unified']" : "[not(@apistyle) or @apistyle='classic']";
-
-		AddXmlNode(
-			root.SelectNodes ("AssemblyInfo" + assemblyInfoNodeFilter).Cast<XmlElement> ().ToArray (),
-			x => x.SelectSingleNode("AssemblyName").InnerText == type.Module.Assembly.Name.Name,
-			x => WriteElementText(x, "AssemblyName", type.Module.Assembly.Name.Name),
-			() => {
-				XmlElement ass = WriteElement(root, "AssemblyInfo", forceNewElement:true);
-				
-				if (MDocUpdater.HasDroppedNamespace (type)) ass.SetAttribute ("apistyle", "unified");
+		AddAssemblyNameToNode (root, type);
 
-				
-
-				return ass;
-			},
-			type);
-
-		foreach(var ass in root.SelectNodes ("AssemblyInfo" + assemblyInfoNodeFilter).Cast<XmlElement> ())
+		string assemblyInfoNodeFilter = MDocUpdater.HasDroppedNamespace (type) ? "[@apistyle='unified']" : "[not(@apistyle) or @apistyle='classic']";
+		Func<XmlElement, bool> assemblyFilter = x => x.SelectSingleNode ("AssemblyName").InnerText == type.Module.Assembly.Name.Name;
+		foreach(var ass in root.SelectNodes ("AssemblyInfo" + assemblyInfoNodeFilter).Cast<XmlElement> ().Where (assemblyFilter))
 		{
 			WriteElementText(ass, "AssemblyName", type.Module.Assembly.Name.Name);
 			if (!no_assembly_versions) {
-				UpdateAssemblyVersions (root, type, true);
+				UpdateAssemblyVersions (ass, type, true);
 			}
 			else {
 				var versions = ass.SelectNodes ("AssemblyVersion").Cast<XmlNode> ().ToList ();
@@ -1654,6 +1652,29 @@ class MDocUpdater : MDocCommand
 		NormalizeWhitespace(root);
 	}
 
+	/// <summary>Adds an AssemblyInfo with AssemblyName node to an XmlElement.</summary>
+	/// <returns>The assembly that was either added, or was already present</returns>
+	static XmlElement AddAssemblyNameToNode (XmlElement root, TypeDefinition type)
+	{
+		return AddAssemblyNameToNode (root, type.Module);
+	}
+
+	/// <summary>Adds an AssemblyInfo with AssemblyName node to an XmlElement.</summary>
+	/// <returns>The assembly that was either added, or was already present</returns>
+	static XmlElement AddAssemblyNameToNode (XmlElement root, ModuleDefinition module)
+	{
+		Func<XmlElement, bool> assemblyFilter = x => x.SelectSingleNode ("AssemblyName").InnerText == module.Assembly.Name.Name;
+		return AddAssemblyXmlNode (
+			root.SelectNodes ("AssemblyInfo").Cast<XmlElement> ().ToArray (), 
+			assemblyFilter, x => WriteElementText (x, "AssemblyName", module.Assembly.Name.Name), 
+			() =>  {
+				XmlElement ass = WriteElement (root, "AssemblyInfo", forceNewElement: true);
+				if (MDocUpdater.HasDroppedNamespace (module))
+					ass.SetAttribute ("apistyle", "unified");
+				return ass;
+			}, module);
+	}
+
 	static readonly string[] TypeNodeOrder = {
 		"TypeSignature",
 		"MemberOfLibrary",
@@ -1709,7 +1730,13 @@ class MDocUpdater : MDocCommand
 		WriteElementText(me, "MemberType", GetMemberType(mi));
 
 		if (!no_assembly_versions) {
-			UpdateAssemblyVersions (me, mi, true);
+			if (!multiassembly)
+				UpdateAssemblyVersions (me, mi, true);
+			else {
+				var node = AddAssemblyNameToNode (me, mi.Module);
+
+				UpdateAssemblyVersionForAssemblyInfo (node, me, new[] { GetAssemblyVersion (mi.Module.Assembly) }, add: true);
+			}
 		}
 		else {
 			ClearElement (me, "AssemblyInfo");
@@ -1743,6 +1770,25 @@ class MDocUpdater : MDocCommand
 		AddXmlNode (relevant, valueMatches, setValue, makeNewNode, type.Module);
 	}
 
+	static XmlElement AddAssemblyXmlNode (XmlElement[] relevant, Func<XmlElement, bool> valueMatches, Action<XmlElement> setValue, Func<XmlElement> makeNewNode, ModuleDefinition module)
+	{
+		bool isUnified = MDocUpdater.HasDroppedNamespace (module);
+		XmlElement thisAssemblyNode = relevant.FirstOrDefault (valueMatches);
+		if (thisAssemblyNode == null) {
+			thisAssemblyNode = makeNewNode ();
+			setValue (thisAssemblyNode);
+		}
+
+		if (isUnified) {
+			thisAssemblyNode.AddApiStyle (ApiStyle.Unified);
+
+			foreach (var otherNodes in relevant.Where (n => n != thisAssemblyNode && n.DoesNotHaveApiStyle (ApiStyle.Unified))) {
+				otherNodes.AddApiStyle (ApiStyle.Classic);
+			}
+		}
+		return thisAssemblyNode;
+	}
+
 	/// <summary>Adds an xml node, reusing the node if it's available</summary>
 	/// <param name="relevant">The existing set of nodes</param>
 	/// <param name="valueMatches">Checks to see if the node's value matches what you're trying to write.</param>
@@ -2307,7 +2353,13 @@ class MDocUpdater : MDocCommand
 		TypeDefinition type = member as TypeDefinition;
 		if (type == null)
 			type = member.DeclaringType as TypeDefinition;
-		return UpdateAssemblyVersions(root, type.Module.Assembly, new string[]{ GetAssemblyVersion (type.Module.Assembly) }, add);
+
+		var versions = new string[] { GetAssemblyVersion (type.Module.Assembly) };
+
+		if (root.LocalName == "AssemblyInfo")
+			return UpdateAssemblyVersionForAssemblyInfo (root, root.ParentNode as XmlElement, versions, add: true);
+		else 
+			return UpdateAssemblyVersions (root, type.Module.Assembly, versions, add);
 	}
 	
 	private static string GetAssemblyVersion (AssemblyDefinition assembly)
@@ -2346,9 +2398,12 @@ class MDocUpdater : MDocCommand
 			thatNode.SetAttribute ("apistyle", "classic");
 		}
 
-		List<XmlNode> matches = e.SelectNodes ("AssemblyVersion").Cast<XmlNode>()
-			.Where(v => Array.IndexOf (assemblyVersions, v.InnerText) >= 0)
-			.ToList ();
+		return UpdateAssemblyVersionForAssemblyInfo (e, root, assemblyVersions, add);
+	}
+
+	static bool UpdateAssemblyVersionForAssemblyInfo (XmlElement e, XmlElement root, string[] assemblyVersions, bool add)
+	{
+		List<XmlNode> matches = e.SelectNodes ("AssemblyVersion").Cast<XmlNode> ().Where (v => Array.IndexOf (assemblyVersions, v.InnerText) >= 0).ToList ();
 		// matches.Count > 0 && add: ignore -- already present
 		if (matches.Count > 0 && !add) {
 			foreach (XmlNode c in matches)
diff --git a/mdoc/Test/DocTest-DropNS-classic.cs b/mdoc/Test/DocTest-DropNS-classic.cs
index 8346834b..13ae56d2 100644
--- a/mdoc/Test/DocTest-DropNS-classic.cs
+++ b/mdoc/Test/DocTest-DropNS-classic.cs
@@ -25,4 +25,8 @@ namespace MyFramework.MyNamespace {
 		public string Name {get;set;}
 	}
 	#endif
+	#if MULTITEST
+	public class OnlyInMulti {
+	}
+	#endif
 }
diff --git a/mdoc/Test/DocTest-DropNS-unified.cs b/mdoc/Test/DocTest-DropNS-unified.cs
index 9b0c364a..0b74be24 100644
--- a/mdoc/Test/DocTest-DropNS-unified.cs
+++ b/mdoc/Test/DocTest-DropNS-unified.cs
@@ -30,4 +30,9 @@ namespace MyNamespace {
 		public string Name {get;set;}
 	}
 	#endif
+
+	#if MULTITEST
+	public class OnlyInMulti {
+	}
+	#endif
 }
diff --git a/mdoc/Test/en.expected-dropns-multi/MyFramework.MyNamespace/MyClass.xml b/mdoc/Test/en.expected-dropns-multi/MyFramework.MyNamespace/MyClass.xml
new file mode 100644
index 00000000..ee429765
--- /dev/null
+++ b/mdoc/Test/en.expected-dropns-multi/MyFramework.MyNamespace/MyClass.xml
@@ -0,0 +1,118 @@
+<Type Name="MyClass" FullName="MyFramework.MyNamespace.MyClass">
+  <TypeSignature Language="C#" Value="public class MyClass" />
+  <TypeSignature Language="ILAsm" Value=".class public auto ansi beforefieldinit MyClass extends System.Object" />
+  <AssemblyInfo apistyle="classic">
+    <AssemblyName>DocTest-DropNS-classic</AssemblyName>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <AssemblyInfo apistyle="classic">
+    <AssemblyName>DocTest-DropNS-classic-multitest</AssemblyName>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <AssemblyInfo apistyle="unified">
+    <AssemblyName>DocTest-DropNS-unified</AssemblyName>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <AssemblyInfo apistyle="unified">
+    <AssemblyName>DocTest-DropNS-unified-multitest</AssemblyName>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <Base>
+    <BaseTypeName>System.Object</BaseTypeName>
+  </Base>
+  <Interfaces />
+  <Docs>
+    <summary>To be added.</summary>
+    <remarks>To be added.</remarks>
+  </Docs>
+  <Members>
+    <Member MemberName=".ctor">
+      <MemberSignature Language="C#" Value="public MyClass ();" />
+      <MemberSignature Language="ILAsm" Value=".method public hidebysig specialname rtspecialname instance void .ctor() cil managed" />
+      <MemberType>Constructor</MemberType>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <Parameters />
+      <Docs>
+        <summary>To be added.</summary>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+    <Member MemberName="Hello">
+      <MemberSignature Language="C#" Value="public float Hello (int value);" />
+      <MemberSignature Language="ILAsm" Value=".method public hidebysig instance float32 Hello(int32 value) cil managed" />
+      <MemberType>Method</MemberType>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>System.Single</ReturnType>
+      </ReturnValue>
+      <Parameters>
+        <Parameter Name="value" Type="System.Int32" />
+      </Parameters>
+      <Docs>
+        <param name="value">To be added.</param>
+        <summary>To be added.</summary>
+        <returns>To be added.</returns>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+    <Member MemberName="MyProperty">
+      <MemberSignature Language="C#" Value="public string MyProperty { get; set; }" />
+      <MemberSignature Language="ILAsm" Value=".property instance string MyProperty" />
+      <MemberType>Property</MemberType>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>System.String</ReturnType>
+      </ReturnValue>
+      <Docs>
+        <summary>To be added.</summary>
+        <value>To be added.</value>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+  </Members>
+</Type>
diff --git a/mdoc/Test/en.expected-dropns-multi/MyFramework.MyNamespace/OnlyInMulti.xml b/mdoc/Test/en.expected-dropns-multi/MyFramework.MyNamespace/OnlyInMulti.xml
new file mode 100644
index 00000000..dbcf1304
--- /dev/null
+++ b/mdoc/Test/en.expected-dropns-multi/MyFramework.MyNamespace/OnlyInMulti.xml
@@ -0,0 +1,40 @@
+<Type Name="OnlyInMulti" FullName="MyFramework.MyNamespace.OnlyInMulti">
+  <TypeSignature Language="C#" Value="public class OnlyInMulti" />
+  <TypeSignature Language="ILAsm" Value=".class public auto ansi beforefieldinit OnlyInMulti extends System.Object" />
+  <AssemblyInfo apistyle="classic">
+    <AssemblyName>DocTest-DropNS-classic-multitest</AssemblyName>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <AssemblyInfo apistyle="unified">
+    <AssemblyName>DocTest-DropNS-unified-multitest</AssemblyName>
+    <AssemblyVersion>0.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <Base>
+    <BaseTypeName>System.Object</BaseTypeName>
+  </Base>
+  <Interfaces />
+  <Docs>
+    <summary>To be added.</summary>
+    <remarks>To be added.</remarks>
+  </Docs>
+  <Members>
+    <Member MemberName=".ctor">
+      <MemberSignature Language="C#" Value="public OnlyInMulti ();" />
+      <MemberSignature Language="ILAsm" Value=".method public hidebysig specialname rtspecialname instance void .ctor() cil managed" />
+      <MemberType>Constructor</MemberType>
+      <AssemblyInfo apistyle="classic">
+        <AssemblyName>DocTest-DropNS-classic-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <AssemblyInfo apistyle="unified">
+        <AssemblyName>DocTest-DropNS-unified-multitest</AssemblyName>
+        <AssemblyVersion>0.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <Parameters />
+      <Docs>
+        <summary>To be added.</summary>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+  </Members>
+</Type>
diff --git a/mdoc/Test/en.expected-dropns-multi/index.xml b/mdoc/Test/en.expected-dropns-multi/index.xml
new file mode 100644
index 00000000..3baf401c
--- /dev/null
+++ b/mdoc/Test/en.expected-dropns-multi/index.xml
@@ -0,0 +1,53 @@
+<Overview>
+  <Assemblies>
+    <Assembly Name="DocTest-DropNS-classic" Version="0.0.0.0">
+      <Attributes>
+        <Attribute>
+          <AttributeName>System.Diagnostics.Debuggable(System.Diagnostics.DebuggableAttribute+DebuggingModes.IgnoreSymbolStoreSequencePoints)</AttributeName>
+        </Attribute>
+        <Attribute>
+          <AttributeName>System.Runtime.CompilerServices.RuntimeCompatibility(WrapNonExceptionThrows=true)</AttributeName>
+        </Attribute>
+      </Attributes>
+    </Assembly>
+    <Assembly Name="DocTest-DropNS-classic-multitest" Version="0.0.0.0">
+      <Attributes>
+        <Attribute>
+          <AttributeName>System.Diagnostics.Debuggable(System.Diagnostics.DebuggableAttribute+DebuggingModes.IgnoreSymbolStoreSequencePoints)</AttributeName>
+        </Attribute>
+        <Attribute>
+          <AttributeName>System.Runtime.CompilerServices.RuntimeCompatibility(WrapNonExceptionThrows=true)</AttributeName>
+        </Attribute>
+      </Attributes>
+    </Assembly>
+    <Assembly Name="DocTest-DropNS-unified" Version="0.0.0.0">
+      <Attributes>
+        <Attribute>
+          <AttributeName>System.Diagnostics.Debuggable(System.Diagnostics.DebuggableAttribute+DebuggingModes.IgnoreSymbolStoreSequencePoints)</AttributeName>
+        </Attribute>
+        <Attribute>
+          <AttributeName>System.Runtime.CompilerServices.RuntimeCompatibility(WrapNonExceptionThrows=true)</AttributeName>
+        </Attribute>
+      </Attributes>
+    </Assembly>
+    <Assembly Name="DocTest-DropNS-unified-multitest" Version="0.0.0.0">
+      <Attributes>
+        <Attribute>
+          <AttributeName>System.Diagnostics.Debuggable(System.Diagnostics.DebuggableAttribute+DebuggingModes.IgnoreSymbolStoreSequencePoints)</AttributeName>
+        </Attribute>
+        <Attribute>
+          <AttributeName>System.Runtime.CompilerServices.RuntimeCompatibility(WrapNonExceptionThrows=true)</AttributeName>
+        </Attribute>
+      </Attributes>
+    </Assembly>
+  </Assemblies>
+  <Remarks>To be added.</Remarks>
+  <Copyright>To be added.</Copyright>
+  <Types>
+    <Namespace Name="MyFramework.MyNamespace">
+      <Type Name="MyClass" Kind="Class" />
+      <Type Name="OnlyInMulti" Kind="Class" />
+    </Namespace>
+  </Types>
+  <Title>Untitled</Title>
+</Overview>
diff --git a/mdoc/Test/en.expected-dropns-multi/ns-MyFramework.MyNamespace.xml b/mdoc/Test/en.expected-dropns-multi/ns-MyFramework.MyNamespace.xml
new file mode 100644
index 00000000..74df75af
--- /dev/null
+++ b/mdoc/Test/en.expected-dropns-multi/ns-MyFramework.MyNamespace.xml
@@ -0,0 +1,6 @@
+<Namespace Name="MyFramework.MyNamespace">
+  <Docs>
+    <summary>To be added.</summary>
+    <remarks>To be added.</remarks>
+  </Docs>
+</Namespace>