From ecb7bbe0ea31888cef2772c6913f2f5065042767 Mon Sep 17 00:00:00 2001
From: Gandalf- <austin.voecks@gmail.com>
Date: Fri, 11 Jan 2019 10:17:44 -0800
Subject: [PATCH] Issue 1330 unsupported echo flags

Issue https://github.com/koalaman/shellcheck/issues/1330

Addresses false positives when quoted arguments to echo begin with what
looks like a flag. Now, warn only when the first argument is a
recognized echo flag when flags are unsupported.
---
 src/ShellCheck/Checks/ShellSupport.hs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/ShellCheck/Checks/ShellSupport.hs b/src/ShellCheck/Checks/ShellSupport.hs
index 7f30224..b642a20 100644
--- a/src/ShellCheck/Checks/ShellSupport.hs
+++ b/src/ShellCheck/Checks/ShellSupport.hs
@@ -145,6 +145,7 @@ prop_checkBashisms62 = verify checkBashisms "#!/bin/sh\nexport -f foo"
 prop_checkBashisms63 = verifyNot checkBashisms "#!/bin/sh\nexport -p"
 prop_checkBashisms64 = verify checkBashisms "#!/bin/sh\nreadonly -a"
 prop_checkBashisms65 = verifyNot checkBashisms "#!/bin/sh\nreadonly -p"
+prop_checkBashisms66 = verifyNot checkBashisms "#!/bin/sh\necho \"-n foo\""
 checkBashisms = ForShell [Sh, Dash] $ \t -> do
     params <- ask
     kludge params t
@@ -231,7 +232,7 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
         warnMsg id "`<file` to read files is"
 
     bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
-        | t `isCommand` "echo" && "-" `isPrefixOf` argString =
+        | t `isCommand` "echo" && elem argString echoFlags =
             unless ("--" `isPrefixOf` argString) $ -- echo "-----"
                 if isDash
                 then
@@ -239,7 +240,9 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
                         warnMsg (getId arg) "echo flags besides -n"
                 else
                     warnMsg (getId arg) "echo flags are"
-      where argString = concat $ oversimplify arg
+      where
+          argString = concat $ oversimplify arg
+          echoFlags = ["-e", "-E", "-s", "-n"]
     bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
         | t `isCommand` "exec" && "-" `isPrefixOf` concat (oversimplify arg) =
             warnMsg (getId arg) "exec flags are"