add a null check that could potentially crash the emulator in the HowMany() function I wrote for path and watch functions. No functional change probably. Also clean up the organization of this method

BizHawk.MultiClient/config/PathManager.cs

@@ -170,8 +170,8 @@ namespace BizHawk.MultiClient
 			int x = NumParentDirectories(path);
 			if (x > 0)
 			{
-				int y = HowMany(path, "..\\");
-				int z = HowMany(workingpath, "\\");
+				int y = StringHelpers.HowMany(path, "..\\");
+				int z = StringHelpers.HowMany(workingpath, "\\");
 				if (y >= z)
 				{
 					//Return drive letter only, working path must be absolute?
@@ -184,36 +184,14 @@ namespace BizHawk.MultiClient
 		public static int NumParentDirectories(string path)
 		{
 			//determine the number of parent directories in path and return result
-			int x = HowMany(path, '\\');
+			int x = StringHelpers.HowMany(path, '\\');
 			if (x > 0)
 			{
-				return HowMany(path, "..\\");
+				return StringHelpers.HowMany(path, "..\\");
 			}
 			return 0;
 		}
 
-		public static int HowMany(string str, string s)
-		{
-			int count = 0;
-			for (int x = 0; x < (str.Length - s.Length); x++)
-			{
-				if (str.Substring(x, s.Length) == s)
-					count++;
-			}
-			return count;
-		}
-
-		public static int HowMany(string str, char c)
-		{
-			int count = 0;
-			for (int x = 0; x < str.Length; x++)
-			{
-				if (str[x] == c)
-					count++;
-			}
-			return count;
-		}
-
 		public static bool IsRecent(string path)
 		{
 			if (path == "%recent%")

BizHawk.MultiClient/tools/WatchCommon.cs

@@ -76,7 +76,7 @@ namespace BizHawk.MultiClient
 					if (s.Length >= 8 && s.Substring(0, 8) == "SystemID")
 						continue;
 
-					z = HowMany(s, '\t');
+					z = StringHelpers.HowMany(s, '\t');
 					if (z == 5)
 					{
 						//If 5, then this is a .wch file format made from another emulator, the first column (watch position) is not needed here
@@ -131,17 +131,6 @@ namespace BizHawk.MultiClient
 			return true;
 		}
 
-		public static int HowMany(string str, char c)
-		{
-			int count = 0;
-			for (int x = 0; x < str.Length; x++)
-			{
-				if (str[x] == c)
-					count++;
-			}
-			return count;
-		}
-
 		public static int GetDomainPos(string name)
 		{
 			//Attempts to find the memory domain by name, if it fails, it defaults to index 0

BizHawk.Util/BizHawk.Util.csproj

@@ -115,6 +115,7 @@
     </Compile>
     <Compile Include="InputValidate.cs" />
     <Compile Include="KeyTurbo.cs" />
+    <Compile Include="StringHelpers.cs" />
     <Compile Include="MiscControls.cs">
       <SubType>Component</SubType>
     </Compile>

BizHawk.Util/StringHelpers.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk
+{
+	public static class StringHelpers
+	{
+		public static int HowMany(string str, char c)
+		{
+			if (!String.IsNullOrEmpty(str))
+			{
+				int count = 0;
+				for (int x = 0; x < str.Length; x++)
+				{
+					if (str[x] == c)
+						count++;
+				}
+				return count;
+			}
+			else
+			{
+				return 0;
+			}
+		}
+
+		public static int HowMany(string str, string s)
+		{
+			int count = 0;
+			for (int x = 0; x < (str.Length - s.Length); x++)
+			{
+				if (str.Substring(x, s.Length) == s)
+					count++;
+			}
+			return count;
+		}
+	}
+}