Merge pull request #3736 from libgit2/cmn/dwim-general-message

refs: provide a more general error message for dwim

src/refs.c

@@ -289,6 +289,9 @@ cleanup:
 			"Could not use '%s' as valid reference name", git_buf_cstr(&name));
 	}
 
+	if (error == GIT_ENOTFOUND)
+		giterr_set(GITERR_REFERENCE, "no reference found for shorthand '%s'", refname);
+
 	git_buf_free(&name);
 	git_buf_free(&refnamebuf);
 	return error;

tests/refs/lookup.c

@@ -58,3 +58,11 @@ void test_refs_lookup__namespace(void)
 	error = git_reference_lookup(&ref, g_repo, "refs/heads/");
 	cl_assert_equal_i(error, GIT_EINVALIDSPEC);
 }
+
+void test_refs_lookup__dwim_notfound(void)
+{
+	git_reference *ref;
+
+	cl_git_fail_with(GIT_ENOTFOUND, git_reference_dwim(&ref, g_repo, "idontexist"));
+	cl_assert_equal_s("no reference found for shorthand 'idontexist'", giterr_last()->message);
+}