5.3 merge

sql/sql_priv.h

@@ -153,6 +153,41 @@
 #define OPTION_ALLOW_BATCH              (ULL(1) << 36) // THD, intern (slave)
 #define OPTION_SKIP_REPLICATION         (ULL(1) << 37) // THD, user
 
+/*
+  Check how many bytes are available on buffer.
+
+  @param buf_start    Pointer to buffer start.
+  @param buf_current  Pointer to the current position on buffer.
+  @param buf_len      Buffer length.
+
+  @return             Number of bytes available on event buffer.
+*/
+template <class T> T available_buffer(const char* buf_start,
+                                      const char* buf_current,
+                                      T buf_len)
+{
+  return buf_len - (buf_current - buf_start);
+}
+
+/*
+  Check if jump value is within buffer limits.
+
+  @param jump         Number of positions we want to advance.
+  @param buf_start    Pointer to buffer start
+  @param buf_current  Pointer to the current position on buffer.
+  @param buf_len      Buffer length.
+
+  @return      True   If jump value is within buffer limits.
+               False  Otherwise.
+*/
+template <class T> bool valid_buffer_range(T jump,
+                                           const char* buf_start,
+                                           const char* buf_current,
+                                           T buf_len)
+{
+  return (jump <= available_buffer(buf_start, buf_current, buf_len));
+}
+
 /* The rest of the file is included in the server only */
 #ifndef MYSQL_CLIENT