Index: /src/python/trunk/Lib/idlelib/PyShell.py
===================================================================
--- /src/python/trunk/Lib/idlelib/PyShell.py	(revision 66617)
+++ /src/python/trunk/Lib/idlelib/PyShell.py	(working copy)
@@ -55,18 +55,24 @@
 except ImportError:
     pass
 else:
-    def idle_showwarning(message, category, filename, lineno):
-        file = warning_stream
+    def idle_showwarning(message, category, filename, lineno,
+                                            file=None, line=None):
+        complaint = warnings.formatwarning(message, category, filename,
+                                           lineno, line)
+        if file is None:
+            file = warning_stream
         try:
-            file.write(warnings.formatwarning(message, category, filename, lineno))
+            file.write(complaint)
         except IOError:
             pass  ## file (probably __stderr__) is invalid, warning dropped.
     warnings.showwarning = idle_showwarning
-    def idle_formatwarning(message, category, filename, lineno):
+    def idle_formatwarning(message, category, filename, lineno, line=None):
         """Format warnings the IDLE way"""
         s = "\nWarning (from warnings module):\n"
         s += '  File \"%s\", line %s\n' % (filename, lineno)
-        line = linecache.getline(filename, lineno).strip()
+        if line is None:
+            line = linecache.getline(filename, lineno)
+        line = line.strip()
         if line:
             s += "    %s\n" % line
         s += "%s: %s\n>>> " % (category.__name__, message)
@@ -87,10 +93,10 @@
     """
     cache = linecache.cache
     save = {}
-    for filename in cache.keys():
-        if filename[:1] + filename[-1:] == '<>':
-            save[filename] = cache[filename]
-    orig_checkcache()
+    for file_name in cache.keys():
+        if file_name[:1] + file_name[-1:] == '<>':
+            save[file_name] = cache[file_name]
+    orig_checkcache(filename)
     cache.update(save)
 
 # Patch linecache.checkcache():
Index: /src/python/trunk/Lib/idlelib/run.py
===================================================================
--- /src/python/trunk/Lib/idlelib/run.py	(revision 66617)
+++ /src/python/trunk/Lib/idlelib/run.py	(working copy)
@@ -24,11 +24,14 @@
 except ImportError:
     pass
 else:
-    def idle_formatwarning_subproc(message, category, filename, lineno):
+    def idle_formatwarning_subproc(message, category, filename, lineno,
+                                                                line=None):
         """Format warnings the IDLE way"""
         s = "\nWarning (from warnings module):\n"
         s += '  File \"%s\", line %s\n' % (filename, lineno)
-        line = linecache.getline(filename, lineno).strip()
+        if line is None:
+            line = linecache.getline(filename, lineno)
+        line = line.strip()
         if line:
             s += "    %s\n" % line
         s += "%s: %s\n" % (category.__name__, message)
Index: /src/python/trunk/Lib/warnings.py
===================================================================
--- /src/python/trunk/Lib/warnings.py	(revision 66617)
+++ /src/python/trunk/Lib/warnings.py	(working copy)
@@ -25,8 +25,9 @@
     """Hook to write a warning to a file; replace if you like."""
     if file is None:
         file = sys.stderr
+    complaint = formatwarning(message, category, filename, lineno, line)
     try:
-        file.write(formatwarning(message, category, filename, lineno, line))
+        file.write(complaint)
     except IOError:
         pass # the file (probably stderr) is invalid - this warning gets lost.
 # Keep a worrking version around in case the deprecation of the old API is
@@ -36,9 +37,10 @@
 def formatwarning(message, category, filename, lineno, line=None):
     """Function to format a warning the standard way."""
     s =  "%s:%s: %s: %s\n" % (filename, lineno, category.__name__, message)
-    line = linecache.getline(filename, lineno) if line is None else line
+    if line is None:
+        line = linecache.getline(filename, lineno)
+    line = line.strip()
     if line:
-        line = line.strip()
         s += "  %s\n" % line
     return s