Fix potential memory leak in mxmlLoadXxx (Issue #278, Issue #279)

CHANGES.md

@@ -1,5 +1,6 @@
 # Changes in Mini-XML 3.2.1
 
+- Fixed potential memory leak in `mxmlLoad*` functions (Issue #278, Issue #279)
 - Fixed `MXML_MINOR_VERSION` value in "mxml.h" (Issue #285)
 - Fixed POSIX threading support for MingW (Issue #287)
 - Fixed some minor memory leaks found by Coverity.

mxml-file.c

@@ -1366,9 +1366,9 @@ mxml_load_data(
     mxml_sax_cb_t   sax_cb,		/* I - SAX callback or MXML_NO_CALLBACK */
     void            *sax_data)		/* I - SAX user data */
 {
-  mxml_node_t	*node,			/* Current node */
-		*first,			/* First node added */
-		*parent;		/* Current parent node */
+  mxml_node_t	*node = NULL,		/* Current node */
+		*first = NULL,		/* First node added */
+		*parent = NULL;		/* Current parent node */
   int		line = 1,		/* Current line number */
 		ch,			/* Character from file */
 		whitespace;		/* Non-zero if whitespace seen */
@@ -1933,8 +1933,13 @@ mxml_load_data(
         {
           (*sax_cb)(node, MXML_SAX_ELEMENT_CLOSE, sax_data);
 
-          if (!mxmlRelease(node) && first == node)
-	    first = NULL;
+          if (!mxmlRelease(node))
+          {
+            if (first == node)
+	      first = NULL;
+
+	    node = NULL;
+	  }
         }
 
        /*
@@ -1981,6 +1986,7 @@ mxml_load_data(
 	  {
 	    mxml_error("Expected > but got '%c' instead for element <%s/> on line %d.", ch, buffer, line);
             mxmlDelete(node);
+            node = NULL;
             goto error;
 	  }
 
@@ -2013,8 +2019,13 @@ mxml_load_data(
         {
           (*sax_cb)(node, MXML_SAX_ELEMENT_CLOSE, sax_data);
 
-          if (!mxmlRelease(node) && first == node)
-            first = NULL;
+          if (!mxmlRelease(node))
+          {
+            if (first == node)
+	      first = NULL;
+
+	    node = NULL;
+	  }
         }
       }
 

testmxml.c

@@ -661,7 +661,7 @@ main(int  argc,				/* I - Number of command-line args */
   memset(event_counts, 0, sizeof(event_counts));
 
   if (argv[1][0] == '<')
-    mxmlSAXLoadString(NULL, argv[1], type_cb, sax_cb, NULL);
+    mxmlRelease(mxmlSAXLoadString(NULL, argv[1], type_cb, sax_cb, NULL));
   else if ((fp = fopen(argv[1], "rb")) == NULL)
   {
     perror(argv[1]);
@@ -673,7 +673,7 @@ main(int  argc,				/* I - Number of command-line args */
     * Read the file...
     */
 
-    mxmlSAXLoadFile(NULL, fp, type_cb, sax_cb, NULL);
+    mxmlRelease(mxmlSAXLoadFile(NULL, fp, type_cb, sax_cb, NULL));
 
     fclose(fp);
   }