From bd77aaa19f0c658254f4e2a0c069a1bfcf0dbea2 Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <mo@bunkus.online>
Date: Sat, 23 Dec 2023 09:33:04 +0100
Subject: [PATCH 1/2] EbmlString::ReadFully: use automatic memory
 management/fewer allocations

(cherry picked from commit ae9bb2580c3e0a79496e72f79185256670abeb95)
---
 src/EbmlString.cpp | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/EbmlString.cpp b/src/EbmlString.cpp
index e1f4597d..66b33383 100644
--- a/src/EbmlString.cpp
+++ b/src/EbmlString.cpp
@@ -142,24 +142,20 @@ filepos_t EbmlString::ReadData(IOCallback & input, ScopeMode ReadFully)
     return GetSize();
 
   if (GetSize() == 0) {
-    Value = "";
-    SetValueIsSet();
+    Value.clear();
+
   } else {
-    auto Buffer = (GetSize() + 1 < std::numeric_limits<std::size_t>::max()) ? new (std::nothrow) char[GetSize() + 1] : nullptr;
-    if (Buffer == nullptr) {
-      // unable to store the data, skip it
-      input.setFilePointer(GetSize(), seek_current);
-    } else {
-      input.readFully(Buffer, GetSize());
-      if (Buffer[GetSize()-1] != '\0') {
-        Buffer[GetSize()] = '\0';
-      }
-      Value = Buffer;
-      delete [] Buffer;
-      SetValueIsSet();
-    }
+    Value.resize(GetSize());
+    std::memset(&Value[0], 0, GetSize());
+    input.readFully(&Value[0], GetSize());
+
+    auto PosNull = Value.find('\0');
+    if (PosNull != std::string::npos)
+      Value.resize(PosNull);
   }
 
+  SetValueIsSet();
+
   return GetSize();
 }
 

From 12c0cebbbda310420a935c021014bffc2b179102 Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <mo@bunkus.online>
Date: Fri, 22 Dec 2023 17:50:15 +0100
Subject: [PATCH 2/2] EbmlUnicodeString: use std::string when reading instead
 of manual memory management

(cherry picked from commit 6b83a0f6f6d1ae7fa14a4f96e70914c1a9686ed4)
---
 src/EbmlUnicodeString.cpp | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/src/EbmlUnicodeString.cpp b/src/EbmlUnicodeString.cpp
index 56f74cec..570af177 100644
--- a/src/EbmlUnicodeString.cpp
+++ b/src/EbmlUnicodeString.cpp
@@ -308,24 +308,16 @@ filepos_t EbmlUnicodeString::ReadData(IOCallback & input, ScopeMode ReadFully)
 
   if (GetSize() == 0) {
     Value = static_cast<UTFstring::value_type>(0);
-    SetValueIsSet();
+
   } else {
-    auto Buffer = (GetSize() + 1 < std::numeric_limits<std::size_t>::max()) ? new (std::nothrow) char[GetSize()+1] : nullptr;
-    if (Buffer == nullptr) {
-      // impossible to read, skip it
-      input.setFilePointer(GetSize(), seek_current);
-    } else {
-      input.readFully(Buffer, GetSize());
-      if (Buffer[GetSize()-1] != 0) {
-        Buffer[GetSize()] = 0;
-      }
-
-      Value.SetUTF8(Buffer); // implicit conversion to std::string
-      delete [] Buffer;
-      SetValueIsSet();
-    }
+    std::string Buffer(static_cast<std::string::size_type>(GetSize()), static_cast<char>(0));
+    input.readFully(&Buffer[0], GetSize());
+
+    Value.SetUTF8(Buffer.c_str()); // Let conversion to std::string cut off at the first 0
   }
 
+  SetValueIsSet();
+
   return GetSize();
 }