From 19f5694277747c514f22256d203f509bb6c1cd08 Mon Sep 17 00:00:00 2001
From: Tom Finegan <tomfinegan@google.com>
Date: Mon, 31 Aug 2015 13:59:35 -0700
Subject: [PATCH] mkvparser: Cluster::Load clean up.

- Remove "// weird"'s.
- Remove needless extra scoping.
- Asserts to error checks.

Change-Id: I5c4d1bbc59d9debe95e1e35e63ff0679335048ff
---
 mkvparser.cpp | 142 +++++++++++++++++++++++---------------------------
 1 file changed, 66 insertions(+), 76 deletions(-)

diff --git a/mkvparser.cpp b/mkvparser.cpp
index 9a08f93..337540c 100644
--- a/mkvparser.cpp
+++ b/mkvparser.cpp
@@ -5650,98 +5650,88 @@ const Track* Tracks::GetTrackByIndex(unsigned long idx) const {
 }
 
 long Cluster::Load(long long& pos, long& len) const {
-  assert(m_pSegment);
-  assert(m_pos >= m_element_start);
+  if (m_pSegment == NULL)
+    return E_PARSE_FAILED;
 
   if (m_timecode >= 0)  // at least partially loaded
     return 0;
 
-  assert(m_pos == m_element_start);
-  assert(m_element_size < 0);
+  if (m_pos != m_element_start || m_element_size >= 0)
+    return E_PARSE_FAILED;
 
   IMkvReader* const pReader = m_pSegment->m_pReader;
-
   long long total, avail;
-
   const int status = pReader->Length(&total, &avail);
 
   if (status < 0)  // error
     return status;
 
-  assert((total < 0) || (avail <= total));
-  assert((total < 0) || (m_pos <= total));  // TODO: verify this
+  if (total >= 0 && (avail > total || m_pos > total))
+    return E_FILE_FORMAT_INVALID;
 
   pos = m_pos;
 
   long long cluster_size = -1;
 
-  {
-    if ((pos + 1) > avail) {
-      len = 1;
-      return E_BUFFER_NOT_FULL;
-    }
-
-    long long result = GetUIntLength(pReader, pos, len);
-
-    if (result < 0)  // error or underflow
-      return static_cast<long>(result);
-
-    if (result > 0)  // underflow (weird)
-      return E_BUFFER_NOT_FULL;
-
-    // if ((pos + len) > segment_stop)
-    //    return E_FILE_FORMAT_INVALID;
-
-    if ((pos + len) > avail)
-      return E_BUFFER_NOT_FULL;
-
-    const long long id_ = ReadUInt(pReader, pos, len);
-
-    if (id_ < 0)  // error
-      return static_cast<long>(id_);
-
-    if (id_ != 0x0F43B675)  // Cluster ID
-      return E_FILE_FORMAT_INVALID;
-
-    pos += len;  // consume id
-
-    // read cluster size
-
-    if ((pos + 1) > avail) {
-      len = 1;
-      return E_BUFFER_NOT_FULL;
-    }
-
-    result = GetUIntLength(pReader, pos, len);
-
-    if (result < 0)  // error
-      return static_cast<long>(result);
-
-    if (result > 0)  // weird
-      return E_BUFFER_NOT_FULL;
-
-    // if ((pos + len) > segment_stop)
-    //    return E_FILE_FORMAT_INVALID;
-
-    if ((pos + len) > avail)
-      return E_BUFFER_NOT_FULL;
-
-    const long long size = ReadUInt(pReader, pos, len);
-
-    if (size < 0)  // error
-      return static_cast<long>(cluster_size);
-
-    if (size == 0)
-      return E_FILE_FORMAT_INVALID;  // TODO: verify this
-
-    pos += len;  // consume length of size of element
-
-    const long long unknown_size = (1LL << (7 * len)) - 1;
-
-    if (size != unknown_size)
-      cluster_size = size;
+  if ((pos + 1) > avail) {
+    len = 1;
+    return E_BUFFER_NOT_FULL;
   }
 
+  long long result = GetUIntLength(pReader, pos, len);
+
+  if (result < 0)  // error or underflow
+    return static_cast<long>(result);
+
+  if (result > 0)
+    return E_BUFFER_NOT_FULL;
+
+  if ((pos + len) > avail)
+    return E_BUFFER_NOT_FULL;
+
+  const long long id_ = ReadUInt(pReader, pos, len);
+
+  if (id_ < 0)  // error
+    return static_cast<long>(id_);
+
+  if (id_ != 0x0F43B675)  // Cluster ID
+    return E_FILE_FORMAT_INVALID;
+
+  pos += len;  // consume id
+
+  // read cluster size
+
+  if ((pos + 1) > avail) {
+    len = 1;
+    return E_BUFFER_NOT_FULL;
+  }
+
+  result = GetUIntLength(pReader, pos, len);
+
+  if (result < 0)  // error
+    return static_cast<long>(result);
+
+  if (result > 0)
+    return E_BUFFER_NOT_FULL;
+
+  if ((pos + len) > avail)
+    return E_BUFFER_NOT_FULL;
+
+  const long long size = ReadUInt(pReader, pos, len);
+
+  if (size < 0)  // error
+    return static_cast<long>(cluster_size);
+
+  if (size == 0)
+    return E_FILE_FORMAT_INVALID;
+
+  pos += len;  // consume length of size of element
+
+  const long long unknown_size = (1LL << (7 * len)) - 1;
+
+  if (size != unknown_size)
+    cluster_size = size;
+
   // pos points to start of payload
   long long timecode = -1;
   long long new_pos = -1;
@@ -5765,7 +5755,7 @@ long Cluster::Load(long long& pos, long& len) const {
     if (result < 0)  // error
       return static_cast<long>(result);
 
-    if (result > 0)  // weird
+    if (result > 0)
       return E_BUFFER_NOT_FULL;
 
     if ((cluster_stop >= 0) && ((pos + len) > cluster_stop))
@@ -5806,7 +5796,7 @@ long Cluster::Load(long long& pos, long& len) const {
     if (result < 0)  // error
       return static_cast<long>(result);
 
-    if (result > 0)  // weird
+    if (result > 0)
       return E_BUFFER_NOT_FULL;
 
     if ((cluster_stop >= 0) && ((pos + len) > cluster_stop))
@@ -5832,7 +5822,7 @@ long Cluster::Load(long long& pos, long& len) const {
 
     // pos now points to start of payload
 
-    if (size == 0)  // weird
+    if (size == 0)
       continue;
 
     if ((cluster_stop >= 0) && ((pos + size) > cluster_stop))