From 9e2365ed14a1f771b25897e48ec755dd06c3673a Mon Sep 17 00:00:00 2001
From: Jack Conger <github@jpco.io>
Date: Mon, 25 May 2026 06:12:23 -0700
Subject: [PATCH] Do not exit from `es -e' due to assignments

When assignments were made to return values, this caused any shell
running with the `-e' flag to exit whenever an assignment was performed.
This makes the `-e' flag effectively unusable.
---
 doc/es.1             | 8 ++++----
 eval.c               | 5 ++++-
 test/tests/option.es | 6 +++---
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/doc/es.1 b/doc/es.1
index b8c5674b..e87d5e1c 100644
--- a/doc/es.1
+++ b/doc/es.1
@@ -2388,8 +2388,8 @@ shell scripts if the kernel does not.
 .TP
 .Cr "%exit-on-false \fIcmd\fP"
 Runs the command, and exits if any command
-(except those executing as the tests of conditional statements)
-returns a non-zero status.
+(except assignments, or those executing as the tests of conditional
+statements) returns a non-zero status.
 (This function is used in the definition of
 .Cr %dispatch
 when the shell is invoked with the
@@ -2901,8 +2901,8 @@ starts with a dash
 .Rc ( - ).
 .TP
 .Cr \-e
-Exit if any command (except those executing as the tests of
-conditional statements) returns a non-zero status.
+Exit if any command (except assignments, or those executing as the
+tests of conditional statements) returns a non-zero status.
 .TP
 .Cr \-v
 Echo all input to standard error.
diff --git a/eval.c b/eval.c
index 015e4ffb..cbb44dc9 100644
--- a/eval.c
+++ b/eval.c
@@ -3,6 +3,7 @@
 #include "es.h"
 
 unsigned long evaldepth = 0, maxevaldepth = MAXmaxevaldepth;
+static Boolean did_assign = FALSE;
 
 static Noreturn failexec(char *file, List *args) {
 	List *fn;
@@ -76,6 +77,7 @@ static List *assign(Tree *varform, Tree *valueform0, Binding *binding0) {
 	}
 
 	RefEnd4(values, vars, binding, valueform);
+	did_assign = TRUE;
 	RefReturn(result);
 }
 
@@ -378,6 +380,7 @@ extern List *eval(List *list0, Binding *binding0, int flags) {
 		return ltrue;
 	}
 	assert(list->term != NULL);
+	did_assign = FALSE;
 
 	if ((cp = getclosure(list->term)) != NULL) {
 		switch (cp->tree->kind) {
@@ -478,7 +481,7 @@ extern List *eval(List *list0, Binding *binding0, int flags) {
 
 done:
 	--evaldepth;
-	if ((flags & eval_exitonfalse) && !istrue(list))
+	if ((flags & eval_exitonfalse) && !istrue(list) && !did_assign)
 		esexit(exitstatus(list));
 	RefEnd2(funcname, binding);
 	RefReturn(list);
diff --git a/test/tests/option.es b/test/tests/option.es
index 600b172d..5e58522b 100644
--- a/test/tests/option.es
+++ b/test/tests/option.es
@@ -20,9 +20,9 @@ test 'es -e' {
 			'{true; {true; {false; true}}}'		false
 
 			# assignments
-			'x = false'				false
-			'fn x {false}'				false
-			'{true; {true; {x = false}; true}}'	false
+			'x = false'				true
+			'fn x {false}'				true
+			'{true; {true; {x = false}; true}}'	true
 			'let (x = false) true'			true
 			'local (x = false) true'		true
 		)) {