add back support for VS 2013 solution format changes

src/Main/SharpDevelop/Project/Solution.cs

@@ -20,6 +20,10 @@ namespace ICSharpCode.SharpDevelop.Project
 		DirectoryName directory;
 		readonly IProjectChangeWatcher changeWatcher;
 		readonly IFileService fileService;
+		internal Version currVSVersion, minVSVersion;
+		
+		static readonly Version DefaultVSVersion = new Version(12, 0, 20827, 3);
+		static readonly Version DefaultMinVSVersion = new Version(10, 0, 40219, 1);
 		
 		public Solution(FileName fileName, IProjectChangeWatcher changeWatcher, IFileService fileService)
 		{
@@ -280,7 +284,9 @@ namespace ICSharpCode.SharpDevelop.Project
 			try {
 				changeWatcher.Disable();
 				using (var solutionWriter = new SolutionWriter(fileName)) {
-					solutionWriter.WriteFormatHeader(ComputeSolutionVersion());
+					var version = ComputeSolutionVersion();
+					solutionWriter.WriteFormatHeader(version);
+					solutionWriter.WriteSolutionVersionProperties(version, currVSVersion ?? DefaultVSVersion, minVSVersion ?? DefaultMinVSVersion);
 					solutionWriter.WriteSolutionItems(this);
 					solutionWriter.WriteGlobalSections(this);
 				}
@@ -307,6 +313,9 @@ namespace ICSharpCode.SharpDevelop.Project
 				if (project.MinimumSolutionVersion > version)
 					version = project.MinimumSolutionVersion;
 			}
+			
+			if ((minVSVersion != null || currVSVersion != null) && version < SolutionFormatVersion.VS2012)
+				version = SolutionFormatVersion.VS2012;
 			return version;
 		}
 		#endregion
@@ -461,5 +470,13 @@ namespace ICSharpCode.SharpDevelop.Project
 		{
 			return "[Solution " + fileName + " with " + projects.Count + " projects]";
 		}
+		
+		public Version VSVersion {
+			get { return currVSVersion; }
+		}
+		
+		public Version MinVSVersion {
+			get { return minVSVersion; }
+		}
 	}
 }

src/Main/SharpDevelop/Project/SolutionLoader.cs

@@ -60,6 +60,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		public void ReadSolution(Solution solution, IProgressMonitor progress)
 		{
 			ReadFormatHeader();
+			ReadVersionProperties(solution);
 			
 			// Read solution folder and project entries:
 			var solutionEntries = new List<ProjectLoadInformation>();
@@ -158,6 +159,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		
 		#region ReadFormatHeader
 		static Regex versionPattern = new Regex(@"^Microsoft Visual Studio Solution File, Format Version\s+(?<Version>[\d\.]+)\s*$");
+		static Regex ideVersionPattern = new Regex(@"((Minimum)?VisualStudioVersion)\s+=\s(?<Version>\d+\.\d+\.\d+\.\d+)");
 		
 		public SolutionFormatVersion ReadFormatHeader()
 		{
@@ -190,6 +192,24 @@ namespace ICSharpCode.SharpDevelop.Project
 			NextLine();
 			return version;
 		}
+		
+		void ReadVersionProperties(Solution solution)
+		{
+			Match match = ideVersionPattern.Match(currentLine);
+			while (match.Success) {
+				Version ideVersion = new Version(match.Result("${Version}"));
+				switch (match.Groups[1].Value) {
+					case "VisualStudioVersion":
+						solution.currVSVersion = ideVersion;
+						break;
+					case "MinimumVisualStudioVersion":
+						solution.minVSVersion = ideVersion;
+						break;
+				}
+				NextLine();
+				match = ideVersionPattern.Match(currentLine);
+			}
+		}
 		#endregion
 		
 		#region ReadSection

src/Main/SharpDevelop/Project/SolutionWriter.cs

@@ -55,6 +55,14 @@ namespace ICSharpCode.SharpDevelop.Project
 			}
 			writer.WriteLine("# SharpDevelop " + RevisionClass.Major + "." + RevisionClass.Minor);
 		}
+		
+		public void WriteSolutionVersionProperties(SolutionFormatVersion version, Version currVSVersion, Version minVSVersion)
+		{
+			if (version >= SolutionFormatVersion.VS2012) {
+				writer.WriteLine("VisualStudioVersion = {0}", currVSVersion);
+				writer.WriteLine("MinimumVisualStudioVersion = {0}", minVSVersion);
+			}
+		}
 		#endregion
 		
 		#region Sections