Fix qvi_bbuff assignment operator. (#272)

The assignment operator needs to make sure that the left-hand side
doesn't have data stored in it.

Signed-off-by: Samuel K. Gutierrez <[email protected]>

src/qvi-bbuff.cc

@@ -17,13 +17,25 @@
 #include "qvi-bbuff.h"
 #include "qvi-utils.h"
 
-qvi_bbuff::qvi_bbuff(void)
+void
+qvi_bbuff::init(void)
 {
+    // Make sure we get rid of any data that may be present.
+    if (m_data) {
+        free(m_data);
+        m_data = nullptr;
+    }
+    m_size = 0;
     m_capacity = s_min_growth;
     m_data = calloc(m_capacity, sizeof(byte_t));
     if (qvi_unlikely(!m_data)) throw qvi_runtime_error();
 }
 
+qvi_bbuff::qvi_bbuff(void)
+{
+    init();
+}
+
 qvi_bbuff::qvi_bbuff(
     const qvi_bbuff &src
 ) : qvi_bbuff()
@@ -34,13 +46,17 @@ qvi_bbuff::qvi_bbuff(
 
 qvi_bbuff::~qvi_bbuff(void)
 {
-    if (m_data) free(m_data);
+    if (m_data) {
+        free(m_data);
+        m_data = nullptr;
+    }
 }
 
 void
 qvi_bbuff::operator=(
     const qvi_bbuff &src
 ) {
+    init();
     const int rc = append(src.m_data, src.m_size);
     if (qvi_unlikely(rc != QV_SUCCESS)) throw qvi_runtime_error();
 }

src/qvi-bbuff.h

@@ -31,6 +31,8 @@ struct qvi_bbuff {
     size_t m_size = 0;
     /** Pointer to data backing store. */
     void *m_data = nullptr;
+    /** Initializes the instance. */
+    void init(void);
 public:
     /** Constructor. */
     qvi_bbuff(void);