CodeCoverage: Apply ccrewrite filter on C# only

Apply Branch-Coverage Code-Contract ccrewrite filter only to C#(.cs)
files

src/AddIns/Analysis/CodeCoverage/Project/Src/CodeCoverageMethodElement.cs

@@ -92,7 +92,7 @@ namespace ICSharpCode.CodeCoverage
 				if (results != null) {
 					this.FileName = results.GetFileName(this.FileID);
 					try {
-						this.FileNameExt = Path.GetExtension(this.FileName);
+						this.FileNameExt = Path.GetExtension(this.FileName).ToLowerInvariant();
 					}
 					catch {}
 					if (cacheFileName != this.FileName) {
@@ -226,6 +226,7 @@ namespace ICSharpCode.CodeCoverage
 		// -> this method SP with lowest Line/Column
 		void getBodyStartSP() {
 			if (this.SequencePoints.Count != 0) {
+				if (this.FileNameExt == ".cs") {
 					foreach (CodeCoverageSequencePoint sp in this.SequencePoints) {
 						if (sp.FileID != this.FileID) continue;
 						if (this.BodyStartSP == null || (sp.Line < this.BodyStartSP.Line) ||
@@ -235,6 +236,10 @@ namespace ICSharpCode.CodeCoverage
 						}
 					}
 				}
+				else {
+					this.BodyStartSP = this.SequencePoints.First();
+				}
+			}
 		}
 
 		// Find method-body last SequencePoint
@@ -242,6 +247,7 @@ namespace ICSharpCode.CodeCoverage
 		// and lowest Offset (when duplicated bw ccrewrite)
 		void getBodyFinalSP() {
 			if (this.SequencePoints.Count != 0) {
+				if (this.FileNameExt == ".cs") {
 					for (int i = this.SequencePoints.Count-1; i > 0; i--) {
 						var sp = this.SequencePoints[i];
 						if (sp.FileID != this.FileID) continue;
@@ -266,6 +272,10 @@ namespace ICSharpCode.CodeCoverage
 						}
 					}
 				}
+				else {
+					this.BodyFinalSP = this.SequencePoints.Last();
+				}
+			}
 		}
 
 		int GetSequencePointsCount() {
@@ -279,6 +289,9 @@ namespace ICSharpCode.CodeCoverage
 			return 0;
 		}
 
+		const string @assert = "Assert";
+		const string @contract = "Contract";
+
 		void GetBranchRatio () {
 
 			this.BranchCoverageRatio = null;
@@ -301,16 +314,17 @@ namespace ICSharpCode.CodeCoverage
 				// SequencePoint is visited and belongs to this method?
 				if (sp.VisitCount != 0 && sp.FileID == this.FileID) {
 
+					if (this.FileNameExt == ".cs") {
+						// Only for C#
+
 						// Don't want branch coverage of ccrewrite(n)
-					// SequencePoint's with offset before and after method body
+						// SequencePoint(s) with offset before and after method body
 						if (sp.Offset < BodyStartSP.Offset ||
 							sp.Offset > BodyFinalSP.Offset) {
 							sp.BranchCoverage = true;
 							continue; // skip
 						}
 
-					if (this.FileNameExt == ".cs") {
-						// 0) Only for C#
 						// 1) Generated "in" code for IEnumerables contains hidden "try/catch/finally" branches that
 						// one do not want or cannot cover by test-case because is handled earlier at same method.
 						// ie: NullReferenceException in foreach loop is pre-handled at method entry, ie. by Contract.Require(items!=null)
@@ -318,13 +332,11 @@ namespace ICSharpCode.CodeCoverage
 						// ie: static methods start sequence point "{" contains compiler generated branches
 						// 3) Exclude Contract class (EnsuresOnThrow/Assert/Assume is inside method body)
 						// 4) Exclude NUnit Assert(.Throws) class
-						const string assert = "Assert";
-						const string contract = "Contract";
 						if (sp.Content == "in" || sp.Content == "{" || sp.Content == "}" ||
-						    sp.Content.StartsWith(assert + ".", StringComparison.Ordinal) ||
-						    sp.Content.StartsWith(assert + " ", StringComparison.Ordinal) ||
-						    sp.Content.StartsWith(contract + ".", StringComparison.Ordinal) ||
-						    sp.Content.StartsWith(contract + " ", StringComparison.Ordinal)
+						    sp.Content.StartsWith(@assert + ".", StringComparison.Ordinal) ||
+						    sp.Content.StartsWith(@assert + " ", StringComparison.Ordinal) ||
+						    sp.Content.StartsWith(@contract + ".", StringComparison.Ordinal) ||
+						    sp.Content.StartsWith(@contract + " ", StringComparison.Ordinal)
 						   ) {
 							sp.BranchCoverage = true;
 							continue; // skip