From: simonpj <unknown>
Date: Fri, 25 Feb 2005 13:54:41 +0000 (+0000)
Subject: [project @ 2005-02-25 13:54:41 by simonpj]
X-Git-Tag: Initial_conversion_from_CVS_complete~1019
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=a42ead96edd42c362778e7420e45e911b379abd6

[project @ 2005-02-25 13:54:41 by simonpj]
Prevent a crash; reason the situation arises in the first place is still unclear
---

diff --git a/ghc/compiler/typecheck/TcSimplify.lhs b/ghc/compiler/typecheck/TcSimplify.lhs
index dd4d215..5db9c0a 100644
--- a/ghc/compiler/typecheck/TcSimplify.lhs
+++ b/ghc/compiler/typecheck/TcSimplify.lhs
@@ -2394,7 +2394,8 @@ addNoInstanceErrs mb_what givens dicts
 		-- Insts for which it is worth suggesting an adding an instance declaration
 		-- Exclude implicit parameters, and tyvar dicts
 
-	add_ors :: [SDoc] -> [SDoc]
+	add_ors :: [SDoc] -> [SDoc]	-- The empty case should not happen
+	add_ors []      = ptext SLIT("[No suggested fixes]")	-- Strange
 	add_ors (f1:fs) = f1 : map (ptext SLIT("or") <+>) fs
 
 addTopAmbigErrs dicts