Fix some empty vector references

streams.h has some methods that can be tricked into dereferencing null pointers or end() iterators. Fix this. Github-Pull: #10250 Rebased-From: f478d98
bitcoin · e23cef0c9469cc360e603a614bb3f0b22c6656bf · sipa committed with luke-jr Apr 13, 2017 · Apr 13, 2017 · e23cef0
1 parent a40d69e
commit e23cef0c9469cc360e603a614bb3f0b22c6656bf
Unified Split

Showing with 6 additions and 2 deletions.

+6 −2 src/streams.h
diff --git a/src/streams.h b/src/streams.h
@@ -248,7 +248,8 @@ class CDataStream
 
     void insert(iterator it, std::vector<char>::const_iterator first, std::vector<char>::const_iterator last)
     {
-        assert(last - first >= 0);
+        if (last == first) return;
+        assert(last - first > 0);
         if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos)
         {
             // special case for inserting at the front when there's room
@@ -261,7 +262,8 @@ class CDataStream
 
     void insert(iterator it, const char* first, const char* last)
     {
-        assert(last - first >= 0);
+        if (last == first) return;
+        assert(last - first > 0);
         if (it == vch.begin() + nReadPos && (unsigned int)(last - first) <= nReadPos)
         {
             // special case for inserting at the front when there's room
@@ -339,6 +341,8 @@ class CDataStream
 
     void read(char* pch, size_t nSize)
     {
+        if (nSize == 0) return;
+
         // Read from the beginning of the buffer
         unsigned int nReadPosNext = nReadPos + nSize;
         if (nReadPosNext >= vch.size())