From 811f90da2fc947adbe9c7363a02727f6eb16b22a Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Fri, 29 Sep 2023 13:13:56 +0300
Subject: [PATCH] Add StringBuilder::append_char.

---
 tdutils/td/utils/StringBuilder.cpp | 18 +++++++++++++++++-
 tdutils/td/utils/StringBuilder.h   |  2 ++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/tdutils/td/utils/StringBuilder.cpp b/tdutils/td/utils/StringBuilder.cpp
index 941394e19..2d86f1118 100644
--- a/tdutils/td/utils/StringBuilder.cpp
+++ b/tdutils/td/utils/StringBuilder.cpp
@@ -8,7 +8,6 @@
 
 #include "td/utils/misc.h"
 #include "td/utils/port/thread_local.h"
-#include "td/utils/Slice.h"
 
 #include <cstdio>
 #include <cstring>
@@ -51,6 +50,23 @@ StringBuilder &StringBuilder::operator<<(Slice slice) {
   return *this;
 }
 
+void StringBuilder::append_char(size_t count, char c) {
+  if (unlikely(!reserve(count))) {
+    if (end_ptr_ < current_ptr_) {
+      on_error();
+      return;
+    }
+    auto available_size = static_cast<size_t>(end_ptr_ + RESERVED_SIZE - 1 - current_ptr_);
+    if (count > available_size) {
+      error_flag_ = true;
+      count = available_size;
+    }
+  }
+
+  MutableSlice(current_ptr_, count).fill(c);
+  current_ptr_ += count;
+}
+
 template <class T>
 static char *print_uint(char *current_ptr, T x) {
   if (x < 100) {
diff --git a/tdutils/td/utils/StringBuilder.h b/tdutils/td/utils/StringBuilder.h
index 3431a01ab..ce82bd990 100644
--- a/tdutils/td/utils/StringBuilder.h
+++ b/tdutils/td/utils/StringBuilder.h
@@ -44,6 +44,8 @@ class StringBuilder {
     *current_ptr_++ = c;
   }
 
+  void append_char(size_t count, char c);
+
   MutableCSlice as_cslice() {
     if (current_ptr_ >= end_ptr_ + RESERVED_SIZE) {
       std::abort();  // shouldn't happen