Supress SC2093 when execfail is set (fixes #3178)

Author: koalaman

src/ShellCheck/Analytics.hs

@@ -1896,7 +1896,9 @@ prop_checkSpuriousExec8 = verifyNot checkSpuriousExec "exec {origout}>&1- >tmp.l
 prop_checkSpuriousExec9 = verify checkSpuriousExec "for file in rc.d/*; do exec \"$file\"; done"
 prop_checkSpuriousExec10 = verifyNot checkSpuriousExec "exec file; r=$?; printf >&2 'failed\n'; return $r"
 prop_checkSpuriousExec11 = verifyNot checkSpuriousExec "exec file; :"
-checkSpuriousExec _ = doLists
+prop_checkSpuriousExec12 = verifyNot checkSpuriousExec "#!/bin/bash\nshopt -s execfail; exec foo; exec bar; echo 'Error'; exit 1;"
+prop_checkSpuriousExec13 = verify checkSpuriousExec "#!/bin/dash\nshopt -s execfail; exec foo; exec bar; echo 'Error'; exit 1;"
+checkSpuriousExec params t = when (not $ hasExecfail params) $ doLists t
   where
     doLists (T_Script _ _ cmds) = doList cmds False
     doLists (T_BraceGroup _ cmds) = doList cmds False

src/ShellCheck/AnalyzerLib.hs

@@ -89,6 +89,8 @@ data Parameters = Parameters {
     hasSetE            :: Bool,
     -- Whether this script has 'set -o pipefail' anywhere.
     hasPipefail        :: Bool,
+    -- Whether this script has 'shopt -s execfail' anywhere.
+    hasExecfail        :: Bool,
     -- A linear (bad) analysis of data flow
     variableFlow       :: [StackData],
     -- A map from Id to Token
@@ -226,6 +228,10 @@ makeParameters spec = params
                 BusyboxSh -> isOptionSet "pipefail" root
                 Sh   -> True
                 Ksh  -> isOptionSet "pipefail" root,
+        hasExecfail =
+            case shellType params of
+                Bash -> isOptionSet "execfail" root
+                _ -> False,
         shellTypeSpecified = isJust (asShellType spec) || isJust (asFallbackShell spec),
         idMap = getTokenMap root,
         parentMap = getParentTree root,