Do not throw exception when working directory cleanup fails

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/AssemblyInfo.cs

@@ -32,7 +32,7 @@ internal sealed partial class AssemblyInfo
 
         /// <summary>
         /// The version number of the .NET Core framework that this assembly targets.
-        /// 
+        ///
         /// This is extracted from the `TargetFrameworkAttribute` of the assembly, e.g.
         /// ```
         /// [assembly:TargetFramework(".NETCoreApp,Version=v7.0")]
@@ -165,6 +165,11 @@ public static AssemblyInfo ReadFromFile(string filename)
                 unsafe
                 {
                     var reader = new MetadataReader(metadata.Pointer, metadata.Length);
+                    if (!reader.IsAssembly)
+                    {
+                        throw new AssemblyLoadException();
+                    }
+
                     var def = reader.GetAssemblyDefinition();
 
                     // This is how you compute the public key token from the full public key.

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DependencyManager.cs

@@ -644,9 +644,25 @@ private void AnalyseSolutions(IEnumerable<string> solutions)
 
         public void Dispose()
         {
-            packageDirectory?.Dispose();
+            try
+            {
+                packageDirectory?.Dispose();
+            }
+            catch (Exception exc)
+            {
+                progressMonitor.LogInfo("Couldn't delete package directory: " + exc.Message);
+            }
             if (cleanupTempWorkingDirectory)
-                tempWorkingDirectory?.Dispose();
+            {
+                try
+                {
+                    tempWorkingDirectory?.Dispose();
+                }
+                catch (Exception exc)
+                {
+                    progressMonitor.LogInfo("Couldn't delete temporary working directory: " + exc.Message);
+                }
+            }
         }
     }
 }