Issue #5078: Avoid redundant call to FormatError()

Modules/_ctypes/callproc.c

@@ -234,14 +234,12 @@ static TCHAR *FormatError(DWORD code)
 }
 
 #ifndef DONT_USE_SEH
-void SetException(DWORD code, EXCEPTION_RECORD *pr)
+static void SetException(DWORD code, EXCEPTION_RECORD *pr)
 {
-	TCHAR *lpMsgBuf;
-	lpMsgBuf = FormatError(code);
-	if(lpMsgBuf) {
-		PyErr_SetFromWindowsErr(code);
-		LocalFree(lpMsgBuf);
-	} else {
+	/* The 'code' is a normal win32 error code so it could be handled by
+	PyErr_SetFromWindowsErr(). However, for some errors, we have additional
+	information not included in the error code. We handle those here and
+	delegate all others to the generic function. */
 	switch (code) {
 	case EXCEPTION_ACCESS_VIOLATION:
 		/* The thread attempted to read from or write
@@ -256,6 +254,7 @@ void SetException(DWORD code, EXCEPTION_RECORD *pr)
 				     "exception: access violation writing %p",
 				     pr->ExceptionInformation[1]);
 		break;
+
 	case EXCEPTION_BREAKPOINT:
 		/* A breakpoint was encountered. */
 		PyErr_SetString(PyExc_WindowsError,
@@ -375,14 +374,11 @@ void SetException(DWORD code, EXCEPTION_RECORD *pr)
 		PyErr_SetString(PyExc_WindowsError,
 				"exception: nocontinuable");
 		break;
+
 	default:
-			printf("error %d\n", code);
-			PyErr_Format(PyExc_WindowsError,
-				     "exception code 0x%08x",
-				     code);
+		PyErr_SetFromWindowsErr(code);
 		break;
 	}
-	}
 }
 
 static DWORD HandleException(EXCEPTION_POINTERS *ptrs,