Implement finalize() method for wmem strbuf.

Change-Id: Ib7a2b0d348b3624f41253e2d0995a4a38a9fe45d
Reviewed-on: https://code.wireshark.org/review/859
Reviewed-by: Evan Huus <eapache@gmail.com>

epan/wmem/wmem_strbuf.c

@@ -232,6 +232,22 @@ wmem_strbuf_get_len(wmem_strbuf_t *strbuf)
     return strbuf->len;
 }
 
+/* Truncates the allocated memory down to the minimal amount, frees the header
+ * structure, and returns a non-const pointer to the raw string. The
+ * wmem_strbuf_t structure cannot be used after this is called.
+ */
+char *
+wmem_strbuf_finalize(wmem_strbuf_t *strbuf)
+{
+    char *ret;
+
+    ret = (char *)wmem_realloc(strbuf->allocator, strbuf->str, strbuf->len+1);
+
+    wmem_free(strbuf->allocator, strbuf);
+
+    return ret;
+}
+
 /*
  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
  *

epan/wmem/wmem_strbuf.h

@@ -89,6 +89,15 @@ WS_DLL_PUBLIC
 gsize
 wmem_strbuf_get_len(wmem_strbuf_t *strbuf);
 
+/** Truncates the allocated memory down to the minimal amount, frees the header
+ *  structure, and returns a non-const pointer to the raw string. The
+ *  wmem_strbuf_t structure cannot be used after this is called. Basically a
+ *  destructor for when you still need the underlying C-string.
+ */
+WS_DLL_PUBLIC
+char *
+wmem_strbuf_finalize(wmem_strbuf_t *strbuf);
+
 /**   @}
  *  @} */
 

epan/wmem/wmem_test.c

@@ -677,6 +677,7 @@ wmem_test_strbuf(void)
     wmem_allocator_t   *allocator;
     wmem_strbuf_t      *strbuf;
     int                 i;
+    char               *str;
 
     allocator = wmem_allocator_new(WMEM_ALLOCATOR_STRICT);
 
@@ -737,6 +738,10 @@ wmem_test_strbuf(void)
     g_assert_cmpstr(wmem_strbuf_get_str(strbuf), ==, "FUZZ3abcd");
     g_assert(wmem_strbuf_get_len(strbuf) == 9);
 
+    str = wmem_strbuf_finalize(strbuf);
+    g_assert_cmpstr(str, ==, "FUZZ3abcd");
+    g_assert(strlen(str) == 9);
+
     wmem_free_all(allocator);
 
     strbuf = wmem_strbuf_new(allocator, "TEST");