Upgrading lzma_sdk to version 9.20.

third_party/lzma_sdk/C/7zBuf2.c

+/* 7zBuf2.c -- Byte Buffer
+2008-10-04 : Igor Pavlov : Public domain */
+
+#include <string.h>
+#include "7zBuf.h"
+
+void DynBuf_Construct(CDynBuf *p)
+{
+  p->data = 0;
+  p->size = 0;
+  p->pos = 0;
+}
+
+void DynBuf_SeekToBeg(CDynBuf *p)
+{
+  p->pos = 0;
+}
+
+int DynBuf_Write(CDynBuf *p, const Byte *buf, size_t size, ISzAlloc *alloc)
+{
+  if (size > p->size - p->pos)
+  {
+    size_t newSize = p->pos + size;
+    Byte *data;
+    newSize += newSize / 4;
+    data = (Byte *)alloc->Alloc(alloc, newSize);
+    if (data == 0)
+      return 0;
+    p->size = newSize;
+    memcpy(data, p->data, p->pos);
+    alloc->Free(alloc, p->data);
+    p->data = data;
+  }
+  memcpy(p->data + p->pos, buf, size);
+  p->pos += size;
+  return 1;
+}
+
+void DynBuf_Free(CDynBuf *p, ISzAlloc *alloc)
+{
+  alloc->Free(alloc, p->data);
+  p->data = 0;
+  p->size = 0;
+  p->pos = 0;
+}