Warn about export/declare/local masking return values.

ShellCheck/Analytics.hs

@@ -207,6 +207,7 @@ nodeChecks = [
     ,checkTildeInPath
     ,checkFindExecWithSingleArgument
     ,checkReturn
+    ,checkMaskedReturns
     ]
 
 
@@ -3261,5 +3262,27 @@ checkFindExecWithSingleArgument _ = checkCommand "find" (const f)
     commandRegex = mkRegex "[ |;]"
 
 
+prop_checkMaskedReturns1 = verify checkMaskedReturns "f() { local a=$(false); }"
+prop_checkMaskedReturns2 = verify checkMaskedReturns "declare a=$(false)"
+prop_checkMaskedReturns3 = verify checkMaskedReturns "declare a=\"`false`\""
+prop_checkMaskedReturns4 = verifyNot checkMaskedReturns "declare a; a=$(false)"
+prop_checkMaskedReturns5 = verifyNot checkMaskedReturns "f() { local -r a=$(false); }"
+checkMaskedReturns _ t@(T_SimpleCommand id _ (cmd:rest)) = potentially $ do
+    name <- getCommandName t
+    guard $ name `elem` ["declare", "export"]
+        || name == "local" && "r" `notElem` getFlags t
+    return $ mapM_ checkArgs rest
+  where
+    checkArgs (T_Assignment id _ _ _ word) | any hasReturn $ getWordParts word =
+        warn id 2155 "Declare and assign separately to avoid masking return values."
+    checkArgs _ = return ()
+
+    hasReturn t = case t of
+        T_Backticked {} -> True
+        T_DollarExpansion {} -> True
+        _ -> False
+checkMaskedReturns _ _ = return ()
+
+
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

ShellCheck/Parser.hs

@@ -950,7 +950,7 @@ readNormalEscaped = called "escaped char" $ do
     pos <- getPosition
     backslash
     do
-        next <- quotable <|> oneOf "?*@!+[]{}.,~"
+        next <- quotable <|> oneOf "?*@!+[]{}.,~#"
         return $ if next == '\n' then "" else [next]
       <|>
         do