SmallString: Fix new buffer size not getting set

src/common/small_string.cpp

@@ -57,56 +57,61 @@ SmallStringBase::~SmallStringBase()
 
 void SmallStringBase::reserve(u32 new_reserve)
 {
-  if (m_buffer_size >= new_reserve)
+  const u32 real_reserve = new_reserve + 1;
+  if (m_buffer_size >= real_reserve)
     return;
 
   if (m_on_heap)
   {
-    char* new_ptr = static_cast<char*>(std::realloc(m_buffer, new_reserve));
+    char* new_ptr = static_cast<char*>(std::realloc(m_buffer, real_reserve));
     if (!new_ptr)
       Panic("Memory allocation failed.");
 
 #ifdef _DEBUG
-    std::memset(new_ptr + m_length, 0, new_reserve - m_length);
+    std::memset(new_ptr + m_length, 0, real_reserve - m_length);
 #endif
     m_buffer = new_ptr;
   }
   else
   {
-    char* new_ptr = static_cast<char*>(std::malloc(new_reserve));
+    char* new_ptr = static_cast<char*>(std::malloc(real_reserve));
     if (!new_ptr)
       Panic("Memory allocation failed.");
 
     if (m_length > 0)
       std::memcpy(new_ptr, m_buffer, m_length);
 #ifdef _DEBUG
-    std::memset(new_ptr + m_length, 0, new_reserve - m_length);
+    std::memset(new_ptr + m_length, 0, real_reserve - m_length);
 #else
     new_ptr[m_length] = 0;
 #endif
     m_buffer = new_ptr;
     m_on_heap = true;
   }
+
+  m_buffer_size = new_reserve;
 }
 
 void SmallStringBase::shrink_to_fit()
 {
-  if (!m_on_heap || m_length == m_buffer_size)
+  const u32 buffer_size = (m_length + 1);
+  if (!m_on_heap || buffer_size == m_buffer_size)
     return;
 
   if (m_length == 0)
   {
     std::free(m_buffer);
+    m_buffer = nullptr;
     m_buffer_size = 0;
     return;
   }
 
-  char* new_ptr = static_cast<char*>(std::realloc(m_buffer, m_length));
+  char* new_ptr = static_cast<char*>(std::realloc(m_buffer, buffer_size));
   if (!new_ptr)
     Panic("Memory allocation failed.");
 
   m_buffer = new_ptr;
-  m_buffer_size = m_length;
+  m_buffer_size = buffer_size;
 }
 
 std::string_view SmallStringBase::view() const