Add null input handling in grpc_json_destroy()

src/core/lib/json/json.cc

@@ -35,24 +35,21 @@ grpc_json* grpc_json_create(grpc_json_type type) {
 }
 
 void grpc_json_destroy(grpc_json* json) {
+  if (json == nullptr) return;
   while (json->child) {
     grpc_json_destroy(json->child);
   }
-
   if (json->next) {
     json->next->prev = json->prev;
   }
-
   if (json->prev) {
     json->prev->next = json->next;
   } else if (json->parent) {
     json->parent->child = json->next;
   }
-
   if (json->owns_value) {
     gpr_free((void*)json->value);
   }
-
   gpr_free(json);
 }
 

src/core/lib/security/credentials/google_default/google_default_credentials.cc

@@ -272,7 +272,7 @@ end:
   GPR_ASSERT((result == nullptr) + (error == GRPC_ERROR_NONE) == 1);
   if (creds_path != nullptr) gpr_free(creds_path);
   grpc_slice_unref_internal(creds_data);
-  if (json != nullptr) grpc_json_destroy(json);
+  grpc_json_destroy(json);
   *creds = result;
   return error;
 }

src/core/lib/security/credentials/jwt/json_token.cc

@@ -121,7 +121,7 @@ grpc_auth_json_key grpc_auth_json_key_create_from_string(
   char* scratchpad = gpr_strdup(json_string);
   grpc_json* json = grpc_json_parse_string(scratchpad);
   grpc_auth_json_key result = grpc_auth_json_key_create_from_json(json);
-  if (json != nullptr) grpc_json_destroy(json);
+  grpc_json_destroy(json);
   gpr_free(scratchpad);
   return result;
 }

src/core/lib/security/credentials/jwt/jwt_verifier.cc

@@ -666,7 +666,7 @@ static void on_keys_retrieved(void* user_data, grpc_error* error) {
   }
 
 end:
-  if (json != nullptr) grpc_json_destroy(json);
+  grpc_json_destroy(json);
   EVP_PKEY_free(verification_key);
   ctx->user_cb(ctx->user_data, status, claims);
   verifier_cb_ctx_destroy(ctx);
@@ -719,7 +719,7 @@ static void on_openid_config_retrieved(void* user_data, grpc_error* error) {
   return;
 
 error:
-  if (json != nullptr) grpc_json_destroy(json);
+  grpc_json_destroy(json);
   ctx->user_cb(ctx->user_data, GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR, nullptr);
   verifier_cb_ctx_destroy(ctx);
 }

src/core/lib/security/credentials/oauth2/oauth2_credentials.cc

@@ -80,7 +80,7 @@ grpc_auth_refresh_token grpc_auth_refresh_token_create_from_string(
   grpc_json* json = grpc_json_parse_string(scratchpad);
   grpc_auth_refresh_token result =
       grpc_auth_refresh_token_create_from_json(json);
-  if (json != nullptr) grpc_json_destroy(json);
+  grpc_json_destroy(json);
   gpr_free(scratchpad);
   return result;
 }
@@ -199,7 +199,7 @@ end:
   }
   if (null_terminated_body != nullptr) gpr_free(null_terminated_body);
   if (new_access_token != nullptr) gpr_free(new_access_token);
-  if (json != nullptr) grpc_json_destroy(json);
+  grpc_json_destroy(json);
   return status;
 }