Rework SWIG interface to handle lifecycle of C pointers correctly.

1 files changed, 48 insertions, 18 deletions

diff --git a/swig/plist.i b/swig/plist.i
index 2347a6d..41ff7cc 100644
--- a/swig/plist.i
+++ b/swig/plist.i
@@ -6,7 +6,17 @@
  #include <plist/plist.h>
 typedef struct {
         plist_t node;
+        char should_keep_plist;
 } PListNode;
+
+PListNode *allocate_wrapper() {
+        PListNode* wrapper = (PListNode*) malloc(sizeof(PListNode));
+        if (wrapper) {
+                memset(wrapper, 0, sizeof(PListNode));
+                return wrapper;
+        }
+        return NULL;
+}
  %}
 
 %include "stdint.i"
@@ -27,7 +37,6 @@ typedef enum {
 } plist_type;
 
 typedef struct {
-        plist_t node;
 } PListNode;
 
 %extend PListNode {             // Attach these functions to struct Vector
@@ -35,12 +44,16 @@ typedef struct {
                 PListNode* node = NULL;
                 switch (t) {
                         case PLIST_ARRAY :
-                                node = (PListNode*) malloc(sizeof(PListNode));
-                                node->node = plist_new_array();
+                                node = allocate_wrapper();
+                                if (node) {
+                                        node->node = plist_new_array();
+                                }
                                 break;
                         case PLIST_DICT :
-                                node = (PListNode*) malloc(sizeof(PListNode));
-                                node->node = plist_new_dict();
+                                node = allocate_wrapper();
+                                if (node) {
+                                        node->node = plist_new_dict();
+                                }
                                 break;
                         default :
                                 node = NULL;
@@ -50,19 +63,21 @@ typedef struct {
         }
 
         PListNode(char* xml) {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
+                PListNode* plist = allocate_wrapper();
                 plist_from_xml(xml, strlen(xml), &plist->node);
                 return plist;
         }
 
         PListNode(char* bin, uint64_t len) {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
+                PListNode* plist = allocate_wrapper();
                 plist_from_bin(bin, len, &plist->node);
                 return plist;
         }
 
         ~PListNode() {
-                plist_free($self->node);
+                if (!$self->should_keep_plist) {
+                        plist_free($self->node);
+                }
                 free($self);
         }
 
@@ -97,20 +112,29 @@ typedef struct {
         }
 
         PListNode* get_first_child() {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
-                plist_get_first_child(&$self->node);
+                PListNode* plist = allocate_wrapper();
+                if (plist) {
+                        plist->node = plist_get_first_child(&$self->node);
+                        plist->should_keep_plist = 1;
+                }
                 return plist;
         }
 
         PListNode* get_next_sibling() {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
-                plist_get_next_sibling(&$self->node);
+                PListNode* plist = allocate_wrapper();
+                if (plist) {
+                        plist->node = plist_get_next_sibling(&$self->node);
+                        plist->should_keep_plist = 1;
+                }
                 return plist;
         }
 
         PListNode* get_prev_sibling() {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
-                plist_get_prev_sibling(&$self->node);
+                PListNode* plist = allocate_wrapper();
+                if (plist) {
+                        plist->node = plist_get_prev_sibling(&$self->node);
+                        plist->should_keep_plist = 1;
+                }
                 return plist;
         }
 
@@ -156,14 +180,20 @@ typedef struct {
         }
 
         PListNode* find_node_by_key(char *s) {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
-                plist = plist_find_node_by_key($self->node, s);
+                PListNode* plist = allocate_wrapper();
+                if (plist) {
+                        plist->node = plist_find_node_by_key($self->node, s);
+                        plist->should_keep_plist = 1;
+                }
                 return plist;
         }
 
         PListNode* find_node_by_string(char* s) {
-                PListNode* plist = (PListNode*) malloc(sizeof(PListNode));
-                plist = plist_find_node_by_string($self->node, s);
+                PListNode* plist = allocate_wrapper();
+                if (plist) {
+                        plist->node = plist_find_node_by_string($self->node, s);
+                        plist->should_keep_plist = 1;
+                }
                 return plist;
         }