Add checks for failure of an allocation function from libxml (#8070)

g_malloc always trap on allocation errors but not xmlMalloc.

tests/tests.c

@@ -71,6 +71,38 @@ fail_logger(const gchar *log_domain, GLogLevelFlags log_level,
 			" «%d»", message, log_domain, log_level);
 }
 
+static xmlFreeFunc free_func;
+static xmlMallocFunc malloc_func;
+static xmlReallocFunc realloc_func;
+static xmlStrdupFunc strdup_func;
+
+void *
+my_malloc(size_t size)
+{
+	void *ptr = malloc_func(size);
+	if (! ptr) {
+		fail("xmlMalloc failed");
+	}
+	return ptr;
+}
+
+void *
+my_realloc(void *mem, size_t size)
+{
+	void *ptr = realloc_func(mem, size);
+	if (! ptr) {
+		fail("xmlRealloc failed");
+	}
+	return ptr;
+}
+
+void
+setup_xml_mem_allocation()
+{
+	xmlMemGet(&free_func, &malloc_func, &realloc_func, &strdup_func);
+	xmlMemSetup(free_func, my_malloc, my_realloc, strdup_func);
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -79,6 +111,7 @@ main(int argc, char *argv[])
 	int i;
 	int dont_fork = 0;
 
+	setup_xml_mem_allocation();
 	for (i=1; i<argc; i++) {
 		if (strcmp(argv[i], "--dontfork") == 0) {
 			dont_fork = 1;