From: simonpj@microsoft.com <unknown>
Date: Thu, 1 Mar 2007 11:45:13 +0000 (+0000)
Subject: Do not go into an infinite loop when pretty-printer finds a negative indent (Trac... 
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=2d52ee06786e5caf0c2d65a4b4bb7c45c6493190

Do not go into an infinite loop when pretty-printer finds a negative indent (Trac #1176)
---

diff --git a/compiler/utils/Pretty.lhs b/compiler/utils/Pretty.lhs
index 31d65f2..0fc817f 100644
--- a/compiler/utils/Pretty.lhs
+++ b/compiler/utils/Pretty.lhs
@@ -225,6 +225,7 @@ allow you to use either GHC or Hugs.  To get GHC, just set the CPP variable
 #define GR      >#
 #define GREQ    >=#
 #define LT      <#
+#define LTEQ    <=#
 #define DIV     `quotInt#`
 
 
@@ -994,11 +995,11 @@ cant_fail = error "easy_display: NoDoc"
 indent n | n GREQ ILIT(8) = '\t' : indent (n MINUS ILIT(8))
          | otherwise      = spaces n
 
-multi_ch ILIT(0) ch = ""
-multi_ch n       ch = ch : multi_ch (n MINUS ILIT(1)) ch
+multi_ch n ch | n LTEQ ILIT(0) = ""
+	      | otherwise      = ch : multi_ch (n MINUS ILIT(1)) ch
 
-spaces ILIT(0) = ""
-spaces n       = ' ' : spaces (n MINUS ILIT(1))
+spaces n | n LTEQ ILIT(0) = ""
+         | otherwise      = ' ' : spaces (n MINUS ILIT(1))
 \end{code}
 
 \begin{code}