From 298919f43a565cc2e130c8cb3f67773f7a54fca1 Mon Sep 17 00:00:00 2001
From: Peter Stephenson
Date: Tue, 8 Nov 2022 14:12:01 +0000
Subject: [PATCH] users/28338: command substitution with alias edge case.
See added regression test.
---
ChangeLog | 5 +++++
Src/lex.c | 8 ++++++++
Test/D08cmdsubst.ztst | 8 ++++++++
3 files changed, 21 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index 7016ca76e..3018706b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2022-11-08 Peter Stephenson
+
+ * users/28338: Src/lex.c, Test/D08cmdsubst.ztst: edge case of an
+ edge case in command expansion of alias.
+
2022-11-06 Bart Schaefer
* 50874: Src/jobs.c: fix handling of tty signals for jobs in
diff --git a/Src/lex.c b/Src/lex.c
index ece02659e..e2f8bcfb1 100644
--- a/Src/lex.c
+++ b/Src/lex.c
@@ -1429,10 +1429,18 @@ gettokstr(int c, int sub)
peek == STRING && lexbuf.ptr[-1] == '}' &&
lexbuf.ptr[-2] != Bnull) {
/* hack to get {foo} command syntax work */
+ /*
+ * Alias expansion when parsing command substitution means that
+ * the case for raw lexical analysis may not be the same.
+ * (Just go with it, OK?)
+ */
+ int lar = lex_add_raw;
+ lex_add_raw = lexbuf_raw.len > 0 && lexbuf_raw.ptr[-1] == '}';
lexbuf.ptr--;
lexbuf.len--;
lexstop = 0;
hungetc('}');
+ lex_add_raw = lar;
}
*lexbuf.ptr = '\0';
DPUTS(cmdsp != ocmdsp, "BUG: gettok: cmdstack changed.");
diff --git a/Test/D08cmdsubst.ztst b/Test/D08cmdsubst.ztst
index 04bf698aa..e415831a0 100644
--- a/Test/D08cmdsubst.ztst
+++ b/Test/D08cmdsubst.ztst
@@ -177,3 +177,11 @@
0:Alias expansion needed in parsing substitutions
>hi
>bye
+
+# This should silently print a blank line; the original problem was
+# a parse error as the last character of the unexpanded alias
+# was erased, symptom: "command not found: W"
+ alias WI='while {false}'
+ eval 'echo $(WI blah)'
+0:Aliases with braces in command substitution can cause havoc
+>