[haskell#121] Fixed duplicating of end of input in unexpected and exp…

…ecting sections

parsec.cabal

@@ -129,6 +129,13 @@ test-suite parsec.
     else
         build-depends: semigroups
 
+test-suite parsec-issue121
+    default-language: Haskell2010
+    type: exitcode-stdio-1.0
+    main-is: issue121.hs
+    hs-source-dirs: test
+    build-depends: base, parsec, containers
+
 test-suite parsec-issue127
     default-language: Haskell2010
     type: exitcode-stdio-1.0

src/Text/Parsec/Error.hs

@@ -187,7 +187,12 @@ showErrorMessages msgOr msgUnknown msgExpecting msgUnExpected msgEndOfInput msgs
       (unExpect,msgs2)    = span ((UnExpect    "") ==) msgs1
       (expect,messages)   = span ((Expect      "") ==) msgs2
 
-      showExpect      = showMany msgExpecting expect
+      cleanedExpect | containsEofInSysUnExpect = filter (\msg -> messageString msg /= msgEndOfInput) expect
+                    | otherwise = expect
+          where
+              containsEofInSysUnExpect = (null unExpect && not (null sysUnExpect)) && null (messageString $ head sysUnExpect)
+
+      showExpect      = showMany msgExpecting cleanedExpect
       showUnExpect    = showMany msgUnExpected unExpect
       showSysUnExpect | not (null unExpect) ||
                         null sysUnExpect = ""
@@ -214,4 +219,4 @@ showErrorMessages msgOr msgUnknown msgExpecting msgUnExpected msgEndOfInput msgs
       separate   _ [m]    = m
       separate sep (m:ms) = m ++ sep ++ separate sep ms
 
-      clean             = nub . filter (not . null)
+      clean             = nub . filter (not . null)

test/issue121.hs

@@ -0,0 +1,37 @@
+module Main (main) where
+
+import Data.Map (fromList)
+import Text.Parsec
+
+sepBy1Try p sep = do
+  x <- p
+  xs <- many (try $ sep *> p)
+  return (x : xs)
+
+key =
+  try (string "byr")
+    <|> try (string "cid")
+    <|> try (string "eyr")
+    <|> try (string "ecl")
+    <|> try (string "hgt")
+    <|> try (string "hcl")
+    <|> try (string "iyr")
+    <|> try (string "pid")
+
+passportKV = try $ do
+  k <- key
+  char ':'
+  v <- many1 (try alphaNum <|> try (char '#'))
+  return (k, v)
+
+passportLine = sepBy1Try passportKV space
+
+passport = do
+  lines <- sepBy1Try passportLine endOfLine
+  return $ fromList [kv | line <- lines, kv <- line]
+
+passports = sepBy1 passport (try (endOfLine *> endOfLine *> pure ()) <|> (endOfLine *> eof *> pure ()))
+
+main = do
+  let raw = "byr:2001 iyr:2011\necl:brn\npid:487702556 hcl:#602927\nhgt:167cm eyr:2026\n"
+  print $ parse passports "(poop)" raw