[librest/wip/baedert/gtask2: 7/8] Add more missing precondition checks

[Timm Bäder <baedert src gnome org>]

commit b11a1664cd4dfcc62b07b4a68adc220fd1eb8305
Author: Timm Bäder <mail baedert org>
Date:   Thu Jul 14 14:22:55 2016 +0200

    Add more missing precondition checks

 rest/rest-proxy.c      |    1 +
 rest/rest-xml-node.c   |   14 ++++++++++++--
 rest/rest-xml-parser.c |    1 +
 3 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/rest/rest-proxy.c b/rest/rest-proxy.c
index ca42aac..ff2b394 100644
--- a/rest/rest-proxy.c
+++ b/rest/rest-proxy.c
@@ -526,6 +526,7 @@ rest_proxy_set_user_agent (RestProxy  *proxy,
                            const char *user_agent)
 {
   g_return_if_fail (REST_IS_PROXY (proxy));
+  g_return_if_fail (user_agent != NULL);
 
   g_object_set (proxy, "user-agent", user_agent, NULL);
 }
diff --git a/rest/rest-xml-node.c b/rest/rest-xml-node.c
index 1a74bcb..9655dc1 100644
--- a/rest/rest-xml-node.c
+++ b/rest/rest-xml-node.c
@@ -215,6 +215,8 @@ const gchar *
 rest_xml_node_get_attr (RestXmlNode *node,
                         const gchar *attr_name)
 {
+  g_return_val_if_fail (attr_name != NULL, NULL);
+
   return g_hash_table_lookup (node->attrs, attr_name);
 }
 
@@ -238,6 +240,7 @@ rest_xml_node_find (RestXmlNode *start,
   const char *tag_interned;
 
   g_return_val_if_fail (start, NULL);
+  g_return_val_if_fail (tag != NULL, NULL);
   g_return_val_if_fail (start->ref_count > 0, NULL);
 
   tag_interned = g_intern_string (tag);
@@ -331,6 +334,7 @@ rest_xml_node_add_child (RestXmlNode *parent, const char *tag)
   RestXmlNode *node;
   char        *escaped;
 
+  g_return_val_if_fail (parent, NULL);
   g_return_val_if_fail (tag && *tag, NULL);
 
   escaped = g_markup_escape_text (tag, -1);
@@ -372,7 +376,11 @@ rest_xml_node_add_attr (RestXmlNode *node,
                         const char  *attribute,
                         const char  *value)
 {
-  g_return_if_fail (node && attribute && *attribute);
+  g_return_if_fail (node);
+  g_return_if_fail (attribute);
+  g_return_if_fail (*attribute);
+  g_return_if_fail (value);
+  g_return_if_fail (*value);
 
   g_hash_table_insert (node->attrs,
                        g_markup_escape_text (attribute, -1),
@@ -389,7 +397,9 @@ rest_xml_node_add_attr (RestXmlNode *node,
 void
 rest_xml_node_set_content (RestXmlNode *node, const char *value)
 {
-  g_return_if_fail (node && value && *value);
+  g_return_if_fail (node);
+  g_return_if_fail (value);
+  g_return_if_fail (*value);
 
   g_free (node->content);
   node->content = g_markup_escape_text (value, -1);
diff --git a/rest/rest-xml-parser.c b/rest/rest-xml-parser.c
index 0e0f467..ffa6ff3 100644
--- a/rest/rest-xml-parser.c
+++ b/rest/rest-xml-parser.c
@@ -91,6 +91,7 @@ rest_xml_parser_parse_from_data (RestXmlParser *parser,
   GQueue nodes = G_QUEUE_INIT;
 
   g_return_val_if_fail (REST_IS_XML_PARSER (parser), NULL);
+  g_return_val_if_fail (data != NULL, NULL);
 
   if (len == -1)
     len = strlen (data);