From 655c4be1c1c4279b96a4af32c7ca704b06c21c74 Mon Sep 17 00:00:00 2001
From: hyenias <58673227+hyenias@users.noreply.github.com>
Date: Tue, 4 May 2021 22:29:19 -0400
Subject: [PATCH] Correct regression for compound arithmetic expressions (re:
 642a1053) (#297)

I did not realize that lvalue->nosub and lvalue->sub variables are
not reset when another assignment occurs later down the line.
Example: (( arr[0][1]+=1, arr[2]=7 ))

src/cmd/ksh93/sh/arith.c: arith():
- For assignment operations, reset lvalue's nosub and sub variables
  so the target for the next assignment is not redirected.

src/cmd/ksh93/tests/arrays2.sh:
- Add in a few regression tests that utilize compound arithmetic
  expressions having at least an assignment operation (+=) followed
  by a normal assignment (=).
---
 src/cmd/ksh93/sh/arith.c       | 5 ++++-
 src/cmd/ksh93/tests/arrays2.sh | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/cmd/ksh93/sh/arith.c b/src/cmd/ksh93/sh/arith.c
index 603876c06..214575de4 100644
--- a/src/cmd/ksh93/sh/arith.c
+++ b/src/cmd/ksh93/sh/arith.c
@@ -234,10 +234,13 @@ static Sfdouble_t arith(const char **ptr, struct lval *lvalue, int type, Sfdoubl
 	    case ASSIGN:
 	    {
 		register Namval_t *np;
-		if (lvalue->nosub > 0 && lvalue->sub) /* indexed array ARITH_ASSIGNOP */
+		if (lvalue->sub && lvalue->nosub > 0) /* indexed array ARITH_ASSIGNOP */
 		{
 			np = (Namval_t*)lvalue->sub; /* use saved subscript reference instead of last worked value */
 			nv_putsub(np, NIL(char*), lvalue->nosub-1);
+			/* reset nosub and sub for next assignment in a compound arithmetic expression */
+			lvalue->nosub = 0;
+			lvalue->sub = 0;
 		}
 		else
 		{
diff --git a/src/cmd/ksh93/tests/arrays2.sh b/src/cmd/ksh93/tests/arrays2.sh
index 2f7fda3bd..6b273d66e 100755
--- a/src/cmd/ksh93/tests/arrays2.sh
+++ b/src/cmd/ksh93/tests/arrays2.sh
@@ -256,6 +256,9 @@ ini() { unset arr; typeset -a arr=((10 20) 6 8); }
 [[ $( ini; ((arr[2]+=arr[0][0])); typeset -p arr) == 'typeset -a arr=((10 20) 6 18)' ]] || err_exit 'ASSIGNOP: arr[2]+=arr[0][0] failed.'
 [[ $( ini; ((arr[2]+=arr[0][1])); typeset -p arr) == 'typeset -a arr=((10 20) 6 28)' ]] || err_exit 'ASSIGNOP: arr[2]+=arr[0][1] failed.'
 [[ $( ini; ((arr[3]+=arr[0][1])); typeset -p arr) == 'typeset -a arr=((10 20) 6 8 20)' ]] || err_exit 'ASSIGNOP: arr[2]+=arr[0][1] failed.'
+[[ $( ini; ((arr[0][1]+=arr[1]+13, arr[2]=42)); typeset -p arr) == 'typeset -a arr=((10 39) 6 42)' ]] || err_exit 'ASSIGNOPs: (_+=,_=_) failed.'
+[[ $( ini; (( (arr[0][1]*=arr[2]) ? arr[0][1]+=arr[1] : arr[1]=7)); typeset -p arr) == 'typeset -a arr=((10 166) 6 8)' ]] || err_exit 'ASSIGNOPs: (_*=_)?_:_ true failed.'
+[[ $( ini; (( (arr[0][2]*=arr[2]) ? arr[0][1]+=arr[1] : arr[1]=7)); typeset -p arr) == 'typeset -a arr=((10 20 0) 7 8)' ]] || err_exit 'ASSIGNOPs: (_*=_)?_:_ false failed.'
 unset arr
 unset -f ini