From bb026cae89ad5bdd861d6ed8134a2e1b86cd3dc0 Mon Sep 17 00:00:00 2001
From: Haiyang Wang <30968392+ocean2811@users.noreply.github.com>
Date: Wed, 23 Aug 2023 00:07:39 +0800
Subject: [PATCH] Decode: fix panic when parsing '0' as a float (#887)

Fixes #886
---
 decode.go           | 2 +-
 unmarshaler_test.go | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/decode.go b/decode.go
index 3a860d0..f0ec3b1 100644
--- a/decode.go
+++ b/decode.go
@@ -318,7 +318,7 @@ func parseFloat(b []byte) (float64, error) {
 	if cleaned[0] == '+' || cleaned[0] == '-' {
 		start = 1
 	}
-	if cleaned[start] == '0' && isDigit(cleaned[start+1]) {
+	if cleaned[start] == '0' && len(cleaned) > start+1 && isDigit(cleaned[start+1]) {
 		return 0, unstable.NewParserError(b, "float integer part cannot have leading zeroes")
 	}
 
diff --git a/unmarshaler_test.go b/unmarshaler_test.go
index 4db58f7..c78ecb2 100644
--- a/unmarshaler_test.go
+++ b/unmarshaler_test.go
@@ -240,6 +240,11 @@ func TestUnmarshal_Floats(t *testing.T) {
 			input:    `0E0`,
 			expected: 0.0,
 		},
+		{
+			desc:     "float zero without decimals",
+			input:    `0`,
+			expected: 0.0,
+		},
 		{
 			desc:     "float fractional with exponent",
 			input:    `6.626e-34`,