Replace Platform.IsMono with actual OS checks

src/Chorus/UI/Sync/SyncStartModel.cs

@@ -165,7 +165,7 @@ internal bool GetUsbStatusLink(IUsbDriveLocator usbDriveLocator, out string mess
 				try
 				{
 					var first = usbDrives[0];
-					if (!Platform.IsMono)
+					if (Platform.IsWindows)
 					{
 						message = string.Format(LocalizationManager.GetString(
 								"GetUsbStatus.DriveInfoAndFreeSpace",

src/LibChorus/FileTypeHandlers/text/TextFileTypeHandler.cs

@@ -17,6 +17,8 @@ namespace Chorus.FileTypeHandlers.text
 	[Export(typeof(IChorusFileTypeHandler))]
 	public class TextFileTypeHandler : IChorusFileTypeHandler
 	{
+		//NB: there is a post-build step in this project which copies the diff3 folder into the output on Windows
+		private static string _diff3Exe = Platform.IsWindows ? "diff3/bin/diff3.exe" : "diff3";
 		internal TextFileTypeHandler()
 		{}
 
@@ -64,14 +66,18 @@ public static string GetRawMerge(string oursPath, string commonPath, string thei
 		{
 			//NB: surrounding with quotes didn't cut it to get past paths with spaces
 
-			return RunProcess("diff3/bin/diff3.exe", "-m " + LongToShortConverter.GetShortPath(oursPath) + " " +
-				LongToShortConverter.GetShortPath(commonPath) + " " +
-				LongToShortConverter.GetShortPath(theirPath));
+			return RunProcess(_diff3Exe, "-m" + QuoteIfNeeded(LongToShortConverter.GetShortPath(oursPath))
+				+ " " + QuoteIfNeeded(LongToShortConverter.GetShortPath(commonPath))
+				+ " " + QuoteIfNeeded(LongToShortConverter.GetShortPath(theirPath)));
 		}
 
-		protected static string SurroundWithQuotes(string path)
+		protected static string QuoteIfNeeded(string arg)
 		{
-			return "\"" + path + "\"";
+			if (arg.Contains(" ")) {
+				return "\"" + arg.Replace("\"", "\\\"") + "\"";
+			} else {
+				return arg;
+			}
 		}
 
 		public static string RunProcess(string filePath, string arguments)
@@ -81,7 +87,6 @@ public static string RunProcess(string filePath, string arguments)
 			p.StartInfo.RedirectStandardError = true;
 			p.StartInfo.RedirectStandardOutput = true;
 
-			//NB: there is a post-build step in this project which copies the diff3 folder into the output
 			p.StartInfo.FileName = filePath;
 			p.StartInfo.Arguments = arguments;
 			p.StartInfo.CreateNoWindow = true;
@@ -154,7 +159,7 @@ private static extern int GetShortPathName(
 
 		public static string GetShortPath(string path)
 		{
-			if (Platform.IsMono)
+			if (!Platform.IsWindows)
 				return path;
 
 			var shortPath = new StringBuilder(255);

src/LibChorus/VcsDrivers/Mercurial/HgRepository.cs

@@ -1138,7 +1138,7 @@ public List<Revision> GetRevisionsFromQueryResultText(string queryResultText)
 					switch (label)
 					{
 						default:
-							if (Platform.IsMono)
+							if (Platform.IsLinux)
 								infiniteLoopChecker++;
 							break;
 						case "changeset":

src/LibChorus/merge/text/PartialTextMerger.cs

@@ -183,7 +183,8 @@ public static string GetRawMerge(string oursPath, string commonPath, string thei
 			p.StartInfo.RedirectStandardOutput = true;
 
 			//NB: there is a post-build step in this project which copies the diff3 folder into the output
-			p.StartInfo.FileName = "diff3/bin/diff3.exe";
+			var filename = File.Exists("diff3/bin/diff3.exe") ? "diff3/bin/diff3.exe" : "diff3"; // On Linux, just use diff3 from the PATH
+			p.StartInfo.FileName = filename;
 			p.StartInfo.Arguments = "-m " + oursPath + " "+commonPath+" "+theirPath;
 			p.StartInfo.CreateNoWindow = true;
 			p.Start();

src/LibChorusTests/VcsDrivers/Mercurial/MercurialTestUtilities.cs

@@ -30,7 +30,7 @@ public void Dispose()
 		private static void UpdateExtensions()
 		{
 			var extensions = new Dictionary<string, string>();
-			if (!Platform.IsMono)
+			if (Platform.IsWindows)
 				extensions.Add("eol", ""); //for converting line endings on windows machines
 			extensions.Add("hgext.graphlog", ""); //for more easily readable diagnostic logs
 			extensions.Add("convert", ""); //for catastrophic repair in case of repo corruption