smart dates: also accept yyyymmdd with no separators

Ledger/Dates.hs

@@ -229,7 +229,7 @@ Assumes any text in the parse stream has been lowercased.
 -}
 smartdate :: GenParser Char st SmartDate
 smartdate = do
-  let dateparsers = [ymd, ym, md, y, d, month, mon, today', yesterday, tomorrow,
+  let dateparsers = [yyyymmdd, ymd, ym, md, y, d, month, mon, today', yesterday, tomorrow,
                      lastthisnextthing
                     ]
   (y,m,d) <- choice $ map try dateparsers
@@ -237,6 +237,15 @@ smartdate = do
 
 datesepchar = oneOf "/-."
 
+yyyymmdd :: GenParser Char st SmartDate
+yyyymmdd = do
+  y <- count 4 digit
+  m <- count 2 digit
+  guard (read m <= 12)
+  d <- count 2 digit
+  guard (read d <= 31)
+  return (y,m,d)
+
 ymd :: GenParser Char st SmartDate
 ymd = do
   y <- many1 digit

Tests.hs

@@ -104,6 +104,7 @@ misc_tests = TestList [
     "1999-12-02"   `gives` "1999/12/02"
     "1999.12.02"   `gives` "1999/12/02"
     "1999/3/2"     `gives` "1999/03/02"
+    "19990302"     `gives` "1999/03/02"
     "2008/2"       `gives` "2008/02/01"
     "20/2"         `gives` "0020/02/01"
     "1000"         `gives` "1000/01/01"