54285: 'let' builtin should return 2 if error occurred

ChangeLog

@@ -1,5 +1,8 @@
 2026-04-07  Jun-ichi Takimoto  <takimoto-j@kba.biglobe.ne.jp>
 
+	* 54285: Src/builtin.c, Test/C01arith.ztst: 'let' builtin
+	should return 2 if error occurred
+
 	* unposted: Doc/Zsh/expn.yo: fix a reference to Arithmetic
 	Evaluation.
 

Src/builtin.c

@@ -7501,8 +7501,11 @@ bin_let(UNUSED(char *name), char **argv, UNUSED(Options ops), UNUSED(int func))
 
     while (*argv)
 	val = matheval(*argv++);
-    /* Errors in math evaluation in let are non-fatal. */
-    errflag &= ~ERRFLAG_ERROR;
+    if (errflag) {
+	/* Errors in math evaluation in let are non-fatal. */
+	errflag &= ~ERRFLAG_ERROR;
+	return 2;
+    }
     /* should test for fabs(val.u.d) < epsilon? */
     return (val.type == MN_INTEGER) ? val.u.l == 0 : val.u.d == 0.0;
 }

Test/C01arith.ztst

@@ -494,7 +494,7 @@
 
   ( unsetopt unset
   let noexist==0 )
-1:Arithmetic, NO_UNSET part 3
+2:Arithmetic, NO_UNSET part 3
 ?(eval):2: noexist: parameter not set
 
   print $(( "6+2" / "1+3" ))