Added cJSON_Duplicate. With commentary

git-svn-id: http://svn.code.sf.net/p/cjson/code@48 e3330c51-1366-4df0-8b21-3ccf24e3d50e

cJSON.c

@@ -529,3 +529,30 @@ cJSON *cJSON_CreateIntArray(int *numbers,int count)				{int i;cJSON *n=0,*p=0,*a
 cJSON *cJSON_CreateFloatArray(float *numbers,int count)			{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && i<count;i++){n=cJSON_CreateNumber(numbers[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
 cJSON *cJSON_CreateDoubleArray(double *numbers,int count)		{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && i<count;i++){n=cJSON_CreateNumber(numbers[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
 cJSON *cJSON_CreateStringArray(const char **strings,int count)	{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && i<count;i++){n=cJSON_CreateString(strings[i]);if(!i)a->child=n;else suffix_object(p,n);p=n;}return a;}
+
+/* Duplication */
+cJSON *cJSON_Duplicate(cJSON *item,int recurse)
+{
+	cJSON *newitem,*cptr,*nptr=0,*newchild;
+	/* Bail on bad ptr */
+	if (!item) return 0;
+	/* Create new item */
+	newitem=cJSON_New_Item();
+	if (!newitem) return 0;
+	/* Copy over all vars */
+	newitem->type=item->type&(~cJSON_IsReference),newitem->valueint=item->valueint,newitem->valuedouble=item->valuedouble;
+	if (item->valuestring)	newitem->valuestring=cJSON_strdup(item->valuestring);
+	if (item->string)		newitem->string=cJSON_strdup(item->string);
+	/* If non-recursive, then we're done! */
+	if (!recurse) return newitem;
+	/* Walk the ->next chain for the child. */
+	cptr=item->child;
+	while (cptr)
+	{
+		newchild=cJSON_Duplicate(cptr,1);		/* Duplicate (with recurse) each item in the ->next chain */
+		if (nptr)	{nptr->next=newchild,newchild->prev=nptr;nptr=newchild;}	/* If newitem->child already set, then crosswire ->prev and ->next and move on */
+		else		{newitem->child=newchild;nptr=newchild;}					/* Set newitem->child and move to it */
+		cptr=cptr->next;
+	}
+	return newitem;
+}

cJSON.h

@@ -114,6 +114,12 @@ extern void   cJSON_DeleteItemFromObject(cJSON *object,const char *string);
 extern void cJSON_ReplaceItemInArray(cJSON *array,int which,cJSON *newitem);
 extern void cJSON_ReplaceItemInObject(cJSON *object,const char *string,cJSON *newitem);
 
+/* Duplicate a cJSON item */
+extern cJSON *cJSON_Duplicate(cJSON *item,int recurse);
+/* Duplicate will create a new, identical cJSON item to the one you pass, in new memory that will
+need to be released. With recurse!=0, it will duplicate any children connected to the item.
+The item->next and ->prev pointers are always zero on return from Duplicate. */
+
 #define cJSON_AddNullToObject(object,name)	cJSON_AddItemToObject(object, name, cJSON_CreateNull())
 #define cJSON_AddTrueToObject(object,name)	cJSON_AddItemToObject(object, name, cJSON_CreateTrue())
 #define cJSON_AddFalseToObject(object,name)		cJSON_AddItemToObject(object, name, cJSON_CreateFalse())