From 520f53019841067fa441124ccb0d5b893b863752 Mon Sep 17 00:00:00 2001
From: Martijn Dekker <martijn@inlv.org>
Date: Tue, 30 Nov 2021 21:43:50 +0100
Subject: [PATCH] lex.c: add default, though it should never happen (re:
 b0282f26)

If a bug is ever introduced that causes a [[ ... ]] operator to be
unhandled by the linter, we should at least avoid writing random
memory contents to standard error. In non-release builds, let's
abort() so the problem can be more easily backtraced.
---
 src/cmd/ksh93/sh/lex.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/cmd/ksh93/sh/lex.c b/src/cmd/ksh93/sh/lex.c
index b77577b87..d04a73927 100644
--- a/src/cmd/ksh93/sh/lex.c
+++ b/src/cmd/ksh93/sh/lex.c
@@ -1411,6 +1411,13 @@ breakloop:
 					    case TEST_GE:
 						alt = ">=";  /* '-ge' --> '>=' */
 						break;
+					    default:
+#if _AST_ksh_release
+						alt = NIL(char*);	/* output '(null)' (should never happen) */
+#else
+						abort();
+#endif
+						break;
 					}
 					errormsg(SH_DICT, ERROR_warn(0), e_lexobsolete4,
 							shp->inlineno, state, alt);