Disable UUOC for cat with unquoted variable (fixes #2333)

src/ShellCheck/ASTLib.hs

@@ -287,14 +287,14 @@ isArrayExpansion (T_DollarBraced _ _ l) =
 isArrayExpansion _ = False
 
 -- Is it possible that this arg becomes multiple args?
-mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f t
+mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f False t
   where
-    f (T_DollarBraced _ _ l) =
+    f quoted (T_DollarBraced _ _ l) =
         let string = concat $ oversimplify l in
-            "!" `isPrefixOf` string
-    f (T_DoubleQuoted _ parts) = any f parts
-    f (T_NormalWord _ parts) = any f parts
-    f _ = False
+            not quoted || "!" `isPrefixOf` string
+    f quoted (T_DoubleQuoted _ parts) = any (f True) parts
+    f quoted (T_NormalWord _ parts) = any (f quoted) parts
+    f _ _ = False
 
 -- Is it certain that this word will becomes multiple words?
 willBecomeMultipleArgs t = willConcatInAssignment t || f t
@@ -302,7 +302,6 @@ willBecomeMultipleArgs t = willConcatInAssignment t || f t
     f T_Extglob {} = True
     f T_Glob {} = True
     f T_BraceExpansion {} = True
-    f (T_DoubleQuoted _ parts) = any f parts
     f (T_NormalWord _ parts) = any f parts
     f _ = False
 

src/ShellCheck/Analytics.hs

@@ -506,7 +506,9 @@ checkWrongArithmeticAssignment _ _ = return ()
 
 prop_checkUuoc1 = verify checkUuoc "cat foo | grep bar"
 prop_checkUuoc2 = verifyNot checkUuoc "cat * | grep bar"
-prop_checkUuoc3 = verify checkUuoc "cat $var | grep bar"
+prop_checkUuoc3 = verify checkUuoc "cat \"$var\" | grep bar"
+prop_checkUuoc3b = verifyNot checkUuoc "cat $var | grep bar"
+prop_checkUuoc3c = verifyNot checkUuoc "cat \"${!var}\" | grep bar"
 prop_checkUuoc4 = verifyNot checkUuoc "cat $var"
 prop_checkUuoc5 = verifyNot checkUuoc "cat \"$@\""
 prop_checkUuoc6 = verifyNot checkUuoc "cat -n | grep bar"
@@ -659,7 +661,7 @@ prop_checkForInQuoted7 = verify checkForInQuoted "for f in ls, grep, mv; do true
 prop_checkForInQuoted8 = verify checkForInQuoted "for f in 'ls', 'grep', 'mv'; do true; done"
 prop_checkForInQuoted9 = verifyNot checkForInQuoted "for f in 'ls,' 'grep,' 'mv'; do true; done"
 checkForInQuoted _ (T_ForIn _ f [T_NormalWord _ [word@(T_DoubleQuoted id list)]] _)
-    | any (\x -> willSplit x && not (mayBecomeMultipleArgs x)) list
+    | any willSplit list && not (mayBecomeMultipleArgs word)
             || maybe False wouldHaveBeenGlob (getLiteralString word) =
         err id 2066 "Since you double quoted this, it will not word split, and the loop will only run once."
 checkForInQuoted _ (T_ForIn _ f [T_NormalWord _ [T_SingleQuoted id _]] _) =