[project @ 2004-05-06 12:27:39 by simonpj]

Add ASSERT

diff --git a/ghc/compiler/rename/RnExpr.lhs b/ghc/compiler/rename/RnExpr.lhs
index 59d0dd1..1b27004 100644 (file)
--- a/ghc/compiler/rename/RnExpr.lhs
+++ b/ghc/compiler/rename/RnExpr.lhs
@@ -952,7 +952,8 @@ segsToStmts :: [Segment [LStmt Name]] -> ([LStmt Name], FreeVars)
 
 segsToStmts [] = ([], emptyFVs)
 segsToStmts ((defs, uses, fwds, ss) : segs)
-  = (new_stmt : later_stmts, later_uses `plusFV` uses)
+  = ASSERT( not (null ss) )
+    (new_stmt : later_stmts, later_uses `plusFV` uses)
   where
     (later_stmts, later_uses) = segsToStmts segs
     new_stmt | non_rec  = head ss