Allow lower-case spellings for boolean fields.

Distribution/PackageDescription/Parse.hs

@@ -182,7 +182,7 @@ executableFieldDescrs =
 binfoFieldDescrs :: [FieldDescr BuildInfo]
 binfoFieldDescrs =
  [ simpleField "buildable"
-           (text . show)      parseReadS
+           (text . show)      parseBool
            buildable          (\val binfo -> binfo{buildable=val})
  , commaListField  "build-tools"
            showDependency     parseBuildTool
@@ -253,7 +253,7 @@ flagFieldDescrs =
         showFreeText     (munch (const True))
         flagDescription  (\val fl -> fl{ flagDescription = val })
     , simpleField "default"
-        (text . show)    parseReadS
+        (text . show)    parseBool
         flagDefault      (\val fl -> fl{ flagDefault = val })
     ]
 

Distribution/ParseUtils.hs

@@ -59,7 +59,7 @@ module Distribution.ParseUtils (
 	parseSepList, parseCommaList, parseOptCommaList,
 	showFilePath, showToken, showTestedWith, showDependency, showFreeText,
 	field, simpleField, listField, commaListField, optsField, liftField,
-	parseReadS, parseReadSQ, parseQuoted,
+	parseReadS, parseReadSQ, parseQuoted, parseBool
   ) where
 
 import Distribution.Compiler (CompilerFlavor)
@@ -477,6 +477,10 @@ parseFilePathQ = parseTokenQ
 parseReadS :: Read a => ReadP r a
 parseReadS = readS_to_P reads
 
+parseBool :: ReadP r Bool
+parseBool = choice [ (string "true" <++ string "True") >> return True
+                   , (string "false" <++ string "False") >> return False ]
+
 parseBuildTool :: ReadP r Dependency
 parseBuildTool = do name <- parseBuildToolNameQ
                     skipSpaces