C#: Fix assembly attribute extraction in standalone mode

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp/Populators/TypeContainerVisitor.cs

@@ -89,8 +89,10 @@ public override void VisitAttributeList(AttributeListSyntax node)
                 SyntaxKind.ModuleKeyword => Entities.AttributeKind.Module,
                 _ => throw new InternalError(node, "Unhandled global target")
             };
-            foreach (var attribute in node.Attributes)
+            var attributes = node.Attributes;
+            for (var i = 0; i < attributes.Count; i++)
             {
+                var attribute = attributes[i];
                 if (attributeLookup.Value(attribute) is AttributeData attributeData)
                 {
                     var ae = Entities.Attribute.Create(Cx, attributeData, outputAssembly, kind);

csharp/ql/test/library-tests/standalone/assemblyattribute/attr.expected

@@ -0,0 +1,2 @@
+| standalone.cs:3:12:3:29 | [assembly: Attribute1(...)] |
+| standalone.cs:9:2:9:11 | [Attribute1(...)] |

csharp/ql/test/library-tests/standalone/assemblyattribute/attr.ql

@@ -0,0 +1,5 @@
+import csharp
+
+from Attribute a
+where a.getType().getName() = "Attribute1Attribute"
+select a

csharp/ql/test/library-tests/standalone/assemblyattribute/options

@@ -0,0 +1 @@
+semmle-extractor-options: --standalone

csharp/ql/test/library-tests/standalone/assemblyattribute/standalone.cs

@@ -0,0 +1,12 @@
+using System;
+
+[assembly: global::Attribute1]
+
+class Attribute1Attribute : Attribute
+{
+}
+
+[Attribute1]
+class A
+{
+}