From 664b2fdff51eab65640e94b0c44e9e70f67ca786 Mon Sep 17 00:00:00 2001
From: kbkpbot <kbkpbot@sina.com>
Date: Sun, 6 Oct 2024 17:29:56 +0800
Subject: [PATCH] fix remove_tail_zeros bug

---
 vlib/strconv/format_mem.c.v | 6 +++++-
 vlib/strconv/format_test.v  | 7 +++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/vlib/strconv/format_mem.c.v b/vlib/strconv/format_mem.c.v
index fc5c2f6c3023ea..1b5dca4200aa1f 100644
--- a/vlib/strconv/format_mem.c.v
+++ b/vlib/strconv/format_mem.c.v
@@ -491,13 +491,17 @@ pub fn remove_tail_zeros(s string) string {
 		if i_s < s.len && s[i_s] == `.` {
 			mut i_s1 := i_s + 1
 			mut sum := 0
+			mut i_s2 := i_s1 // last non-zero index after `.`
 			for i_s1 < s.len && s[i_s1] >= `0` && s[i_s1] <= `9` {
 				sum += s[i_s1] - u8(`0`)
+				if s[i_s1] != `0` {
+					i_s2 = i_s1
+				}
 				i_s1++
 			}
 			// decimal part must be copied
 			if sum > 0 {
-				for c_i in i_s .. i_s1 {
+				for c_i in i_s .. i_s2 + 1 {
 					buf[i_d] = s[c_i]
 					i_d++
 				}
diff --git a/vlib/strconv/format_test.v b/vlib/strconv/format_test.v
index 9a815981b7ac35..ffd469a90ab38f 100644
--- a/vlib/strconv/format_test.v
+++ b/vlib/strconv/format_test.v
@@ -119,3 +119,10 @@ fn test_sprintf_with_escape() {
 	s := unsafe { strconv.v_sprintf('%d is 100%% awesome', n) }
 	assert s == '69 is 100% awesome'
 }
+
+fn test_remove_tail_zeros() {
+	assert strconv.remove_tail_zeros('1.234000000000') == '1.234'
+	assert strconv.remove_tail_zeros('1.0000000') == '1'
+	assert strconv.remove_tail_zeros('1234') == '1234'
+	assert strconv.remove_tail_zeros('1.00000000007') == '1.00000000007'
+}