From 56a299df79b88b7038a8a5f79f3c0c401f6d63d8 Mon Sep 17 00:00:00 2001
From: hallgren <hallgren@chalmers.se>
Date: Wed, 3 Apr 2013 06:42:08 +0000
Subject: [PATCH] Prevent Unicode characters in warning messages from stopping
 grammar compilation

When compiling a grammar containing characters that are not supported in the
current locale, warning messages could cause GF fail with

  hPutChar: invalid argument (Invalid or incomplete multibyte or wide character)

With this quick fix, warning messages that can not be displayed are silently
truncated instead, and compilation continues.
---
 src/compiler/GF/Compile.hs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/compiler/GF/Compile.hs b/src/compiler/GF/Compile.hs
index 84aa3d7d9..91781d3ce 100644
--- a/src/compiler/GF/Compile.hs
+++ b/src/compiler/GF/Compile.hs
@@ -83,10 +83,12 @@ intermOut opts d doc
 
 warnOut opts warnings
   | null warnings = return ()
-  | otherwise     = ioeIO (hPutStrLn stderr $ 
-                                     if flag optVerbosity opts == Normal
-                                       then ('\n':warnings)
-                                       else warnings)
+  | otherwise     = ioeIO $ hPutStrLn stderr ws `catch` oops
+  where
+    oops _ = hPutStrLn stderr "" -- prevent crash on character encoding problem
+    ws = if flag optVerbosity opts == Normal
+         then '\n':warnings
+         else warnings
 
 -- | the environment
 type CompileEnv = (Int,SourceGrammar,ModEnv)