mdoc: Better null handling.

For a case where an invalid frameworks.xml entry caused a vague error message. Closes #79

1 files changed, 8 insertions, 2 deletions

diff --git a/mdoc/Mono.Documentation/MDocUpdater.cs b/mdoc/Mono.Documentation/MDocUpdater.cs
index c7e5d64b..915adfca 100644
--- a/mdoc/Mono.Documentation/MDocUpdater.cs
+++ b/mdoc/Mono.Documentation/MDocUpdater.cs
@@ -979,8 +979,14 @@ namespace Mono.Documentation
             }
 
             string defaultTitle = "Untitled";
-            if (processedAssemblyCount == 1)
-                defaultTitle = assemblies[0].Assemblies.First ().Name.Name;
+            if (processedAssemblyCount == 1 && assemblies[0] != null)

+            {

+                var assembly = assemblies[0].Assemblies.FirstOrDefault();

+                if (assembly != null) 

+                    defaultTitle = assembly.Name.Name;

+                else

+                    Warning($"Seems to be an issue with assembly group '{assemblies[0].Name}'. There are no assemblies loaded.");

+            }
             WriteElementInitialText (index.DocumentElement, "Title", defaultTitle);
 
             SortIndexEntries (index_types);