Improved robustness of PesFile.OpenFile()

PesFile/PesFile.cs

@@ -111,10 +111,6 @@ namespace PesFile
 
         private void OpenFile(string filename)
         {
-#if !DEBUG
-            try
-            {
-#endif
             _filename = filename;
             fileIn = new System.IO.BinaryReader(System.IO.File.Open(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read));
 
@@ -138,9 +134,25 @@ namespace PesFile
             {
                 versionString += fileIn.ReadChar();
             }
-                pesVersion = Convert.ToUInt16(versionString);
+            if(!UInt16.TryParse(versionString, out pesVersion))
+            {
+                // This is not a file that we can read
+                readyStatus = statusEnum.ParseError;
+                lastError = "PES version is not the correct format";
+                fileIn.Close();
+                return;
+            }
                 
             int pecstart = fileIn.ReadInt32();
+            // Sanity check on PEC start position
+            if(fileIn.BaseStream.Length < (pecstart + 532))
+            {
+                // This file is probably truncated
+                readyStatus = statusEnum.ParseError;
+                lastError = "File appears to be truncated (PEC section is beyond end of file)";
+                fileIn.Close();
+                return;
+            }
 
             // Read number of colors in this design
             fileIn.BaseStream.Position = pecstart + 48;
@@ -284,28 +296,6 @@ namespace PesFile
 
             // Close the file
             fileIn.Close();
-
-#if !DEBUG
-            }
-            catch (System.IO.IOException ioex)
-            {
-                readyStatus = statusEnum.IOError;
-                lastError = ioex.Message;
-                if (fileIn != null)
-                {
-                    fileIn.Close();
-                }
-            }
-            catch (Exception ex)
-            {
-                readyStatus = statusEnum.ParseError;
-                lastError = ex.Message;
-                if (fileIn != null)
-                {
-                    fileIn.Close();
-                }
-            }
-#endif
         }
 
         public int GetWidth()