pycolor: Wrong filename given -> print error

When a user wanted to colorize a file, which doesn't exist, IPython
would crash. This commit changes this, so the user gets a usefull
message about the wrong filename.

This fixes RH bug  #628742.

Signed-off-by: Thomas Spura <[e-mail]>

IPython/utils/PyColorize.py

@@ -277,7 +277,11 b' If no filename is given, or if filename is -, read standard input."""'
     if fname == '-':
         stream = sys.stdin
     else:
-        stream = file(fname)
+        try:
+            stream = file(fname)
+        except IOError,msg:
+            print >> sys.stderr, msg
+            sys.exit(1)
 
     parser = Parser()