fix: avoid panic after calling WordsSeq (#2810)

CHANGELOG.md

@@ -13,6 +13,7 @@
   `:` elsewhere (#2406, #2408 by @solvingj).
 - Update the shell interpreter with a regression fix (#2812, #2832 by
   @andreynering).
+- Fix potential panic with the shell interpreter (#2810 by @trulede).
 
 ## v3.50.0 - 2026-04-13
 

internal/execext/exec.go

@@ -127,7 +127,10 @@ func ExpandFields(s string) ([]string, error) {
 	s = escape(s)
 	p := syntax.NewParser()
 	var words []*syntax.Word
-	for w := range p.WordsSeq(strings.NewReader(s)) {
+	for w, err := range p.WordsSeq(strings.NewReader(s)) {
+		if err != nil {
+			return nil, err
+		}
 		words = append(words, w)
 	}
 	cfg := &expand.Config{