fixup! refactor package version metric creation

Fix memory access error - if package with the same name already exists in
txn->php_packages, nr_php_packages_add_package will return a pointer to
that package and not the one passed in.

Author: lavarou

axiom/nr_php_packages.c

@@ -88,14 +88,15 @@ nr_php_packages_t* nr_php_packages_create() {
   return h;
 }
 
-void nr_php_packages_add_package(nr_php_packages_t* h, nr_php_package_t* p) {
+nr_php_package_t* nr_php_packages_add_package(nr_php_packages_t* h,
+                                              nr_php_package_t* p) {
   nr_php_package_t* package;
   if (NULL == h) {
-    return;
+    return NULL;
   }
 
   if (NULL == p || NULL == p->package_name || NULL == p->package_version) {
-    return;
+    return NULL;
   }
 
   // If package with the same key already exists, we will check if the value is
@@ -108,10 +109,11 @@ void nr_php_packages_add_package(nr_php_packages_t* h, nr_php_package_t* p) {
       package->package_version = nr_strdup(p->package_version);
     }
     nr_php_package_destroy(p);
-    return;
+    return package;
   }
 
   nr_hashmap_set(h->data, p->package_name, nr_strlen(p->package_name), p);
+  return p;
 }
 
 char* nr_php_package_to_json(nr_php_package_t* package) {

axiom/nr_php_packages.h

@@ -87,10 +87,10 @@ extern nr_php_packages_t* nr_php_packages_create(void);
  *           2. A pointer to the php package that needs to be added to the
  *              collection
  *
- * Returns : Nothing
+ * Returns : pointer to added package on success or NULL otherwise.
  */
-extern void nr_php_packages_add_package(nr_php_packages_t* h,
-                                        nr_php_package_t* p);
+extern nr_php_package_t* nr_php_packages_add_package(nr_php_packages_t* h,
+                                                     nr_php_package_t* p);
 
 /*
  * Purpose : Destroy/free the collection

axiom/nr_txn.c

@@ -3510,8 +3510,7 @@ nr_php_package_t* nr_txn_add_php_package_from_source(
   }
 
   p = nr_php_package_create_with_source(package_name, package_version, source);
-  nr_php_packages_add_package(txn->php_packages, p);
-  return p;
+  return nr_php_packages_add_package(txn->php_packages, p);
 }
 
 nr_php_package_t* nr_txn_add_php_package(nrtxn_t* txn,

axiom/tests/test_txn.c

@@ -8597,6 +8597,8 @@ static void test_nr_txn_add_php_package(void) {
   char* package_name4 = "Wordpress";
   char* package_version4 = PHP_PACKAGE_VERSION_UNKNOWN;
   nrtxn_t* txn = new_txn(0);
+  nr_php_package_t* p1 = NULL;
+  nr_php_package_t* p2 = NULL;
 
   /*
    * NULL parameters: ensure it does not crash
@@ -8621,6 +8623,13 @@ static void test_nr_txn_add_php_package(void) {
 
   nr_free(json);
   nr_txn_destroy(&txn);
+
+  txn = new_txn(0);
+  p1 = nr_txn_add_php_package(txn, package_name1, package_version1);
+  p2 = nr_txn_add_php_package(txn, package_name1, package_version2);
+  tlib_pass_if_ptr_equal(
+      "same package name, different version, add returns same pointer", p1, p2);
+  nr_txn_destroy(&txn);
 }
 
 tlib_parallel_info_t parallel_info