Address some memory leaks

src/core/lib/security/credentials/credentials.c

@@ -58,6 +58,7 @@ grpc_credentials_metadata_request *grpc_credentials_metadata_request_create(
     void *user_data) {
   grpc_credentials_metadata_request *r =
       gpr_malloc(sizeof(grpc_credentials_metadata_request));
+  memset(&r->response, 0, sizeof(r->response));
   r->creds = grpc_call_credentials_ref(creds);
   r->cb = cb;
   r->user_data = user_data;
@@ -67,6 +68,7 @@ grpc_credentials_metadata_request *grpc_credentials_metadata_request_create(
 void grpc_credentials_metadata_request_destroy(
     grpc_credentials_metadata_request *r) {
   grpc_call_credentials_unref(r->creds);
+  grpc_http_response_destroy(&r->response);
   gpr_free(r);
 }
 

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

@@ -113,6 +113,7 @@ static int is_stack_running_on_compute_engine(void) {
   detector.is_done = 0;
   detector.success = 0;
 
+  memset(&detector.response, 0, sizeof(detector.response));
   memset(&request, 0, sizeof(grpc_httpcli_request));
   request.host = GRPC_COMPUTE_ENGINE_DETECTION_HOST;
   request.http.path = "/";
@@ -150,6 +151,7 @@ static int is_stack_running_on_compute_engine(void) {
   g_polling_mu = NULL;
 
   gpr_free(detector.pollset);
+  grpc_http_response_destroy(&detector.response);
 
   return detector.success;
 }

test/core/security/credentials_test.c

@@ -157,7 +157,7 @@ static grpc_httpcli_response http_response(int status, const char *body) {
   grpc_httpcli_response response;
   memset(&response, 0, sizeof(grpc_httpcli_response));
   response.status = status;
-  response.body = (char *)body;
+  response.body = gpr_strdup((char *)body);
   response.body_length = strlen(body);
   return response;
 }
@@ -247,6 +247,7 @@ static void test_oauth2_token_fetcher_creds_parsing_ok(void) {
                                "Bearer ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_") ==
              0);
   grpc_credentials_md_store_unref(token_md);
+  grpc_http_response_destroy(&response);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_bad_http_status(void) {
@@ -257,6 +258,7 @@ static void test_oauth2_token_fetcher_creds_parsing_bad_http_status(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
+  grpc_http_response_destroy(&response);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_empty_http_body(void) {
@@ -266,6 +268,7 @@ static void test_oauth2_token_fetcher_creds_parsing_empty_http_body(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
+  grpc_http_response_destroy(&response);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_invalid_json(void) {
@@ -279,6 +282,7 @@ static void test_oauth2_token_fetcher_creds_parsing_invalid_json(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
+  grpc_http_response_destroy(&response);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_missing_token(void) {
@@ -291,6 +295,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
+  grpc_http_response_destroy(&response);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_missing_token_type(void) {
@@ -304,6 +309,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token_type(void) {
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
+  grpc_http_response_destroy(&response);
 }
 
 static void test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime(
@@ -317,6 +323,7 @@ static void test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime(
   GPR_ASSERT(grpc_oauth2_token_fetcher_credentials_parse_server_response(
                  &response, &token_md, &token_lifetime) ==
              GRPC_CREDENTIALS_ERROR);
+  grpc_http_response_destroy(&response);
 }
 
 static void check_metadata(expected_md *expected, grpc_credentials_md *md_elems,
@@ -902,8 +909,8 @@ static int default_creds_gce_detection_httpcli_get_success_override(
     grpc_httpcli_response *response) {
   *response = http_response(200, "");
   grpc_http_header *headers = gpr_malloc(sizeof(*headers) * 1);
-  headers[0].key = "Metadata-Flavor";
-  headers[0].value = "Google";
+  headers[0].key = gpr_strdup("Metadata-Flavor");
+  headers[0].value = gpr_strdup("Google");
   response->hdr_count = 1;
   response->hdrs = headers;
   GPR_ASSERT(strcmp(request->http.path, "/") == 0);