util/envlist had no test coverage. Add tests/unit/test-envlist
exercising the public envlist API and pinning down the prefix-match
hazard fixed in the previous commit:
- envlist_unsetenv("FOO") must not remove an entry named "FOOBAR";
- envlist_setenv("FOO=...") must not replace an existing "FOOBAR=..."
entry placed earlier in the list (envlist_setenv() inserts at the
head, so the first prefix match wins under the old strncmp rule).
Also cover the rest of the contract: head-insertion order observed
through envlist_to_environ(), replacement of an existing variable,
the count argument of envlist_to_environ(), and the documented EINVAL
paths (NULL inputs, setenv without '=', unsetenv with '=').
Signed-off-by: Denis V. Lunev <[email protected]>
Cc: Stefan Hajnoczi <[email protected]>
Cc: Markus Armbruster <[email protected]>
Cc: Paolo Bonzini <[email protected]>
---
tests/unit/meson.build | 1 +
tests/unit/test-envlist.c | 196 ++++++++++++++++++++++++++++++++++++++
2 files changed, 197 insertions(+)
create mode 100644 tests/unit/test-envlist.c
diff --git a/tests/unit/meson.build b/tests/unit/meson.build
index de64f9501f..01cc540a45 100644
--- a/tests/unit/meson.build
+++ b/tests/unit/meson.build
@@ -49,6 +49,7 @@ tests = {
'test-qapi-util': [],
'test-interval-tree': [],
'test-fifo': [],
+ 'test-envlist': [],
}
if have_system or have_tools
diff --git a/tests/unit/test-envlist.c b/tests/unit/test-envlist.c
new file mode 100644
index 0000000000..53813dd4de
--- /dev/null
+++ b/tests/unit/test-envlist.c
@@ -0,0 +1,196 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * envlist tests
+ *
+ * Copyright 2026 Virtuozzo International GmbH
+ *
+ * Authors:
+ * Denis V. Lunev <[email protected]>
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/envlist.h"
+
+static void free_environ(char **env)
+{
+ char **p;
+
+ for (p = env; *p != NULL; p++) {
+ g_free(*p);
+ }
+ g_free(env);
+}
+
+static const char *find_env(char **env, const char *name)
+{
+ size_t name_len = strlen(name);
+ char **p;
+
+ for (p = env; *p != NULL; p++) {
+ if (strncmp(*p, name, name_len) == 0 && (*p)[name_len] == '=') {
+ return *p + name_len + 1;
+ }
+ }
+ return NULL;
+}
+
+static void test_envlist_basic(void)
+{
+ envlist_t *el = envlist_create();
+ char **env;
+ size_t count;
+
+ /* empty list */
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 0);
+ g_assert_null(env[0]);
+ free_environ(env);
+
+ /* add */
+ g_assert_cmpint(envlist_setenv(el, "A=1"), ==, 0);
+ g_assert_cmpint(envlist_setenv(el, "B=2"), ==, 0);
+
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 2);
+ g_assert_cmpstr(find_env(env, "A"), ==, "1");
+ g_assert_cmpstr(find_env(env, "B"), ==, "2");
+ free_environ(env);
+
+ /* replace */
+ g_assert_cmpint(envlist_setenv(el, "A=42"), ==, 0);
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 2);
+ g_assert_cmpstr(find_env(env, "A"), ==, "42");
+ g_assert_cmpstr(find_env(env, "B"), ==, "2");
+ free_environ(env);
+
+ /* unset existing */
+ g_assert_cmpint(envlist_unsetenv(el, "A"), ==, 0);
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 1);
+ g_assert_null(find_env(env, "A"));
+ g_assert_cmpstr(find_env(env, "B"), ==, "2");
+ free_environ(env);
+
+ /* unset non-existing is a no-op success */
+ g_assert_cmpint(envlist_unsetenv(el, "NOPE"), ==, 0);
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 1);
+ free_environ(env);
+
+ envlist_free(el);
+}
+
+/*
+ * envlist_setenv() inserts at the head; envlist_to_environ() walks
+ * head-to-tail, so the last setenv comes out first.
+ */
+static void test_envlist_head_insertion_order(void)
+{
+ envlist_t *el = envlist_create();
+ char **env;
+ size_t count;
+
+ g_assert_cmpint(envlist_setenv(el, "A=1"), ==, 0);
+ g_assert_cmpint(envlist_setenv(el, "B=2"), ==, 0);
+ g_assert_cmpint(envlist_setenv(el, "C=3"), ==, 0);
+
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 3);
+ g_assert_cmpstr(env[0], ==, "C=3");
+ g_assert_cmpstr(env[1], ==, "B=2");
+ g_assert_cmpstr(env[2], ==, "A=1");
+ g_assert_null(env[3]);
+
+ free_environ(env);
+ envlist_free(el);
+}
+
+static void test_envlist_einval(void)
+{
+ envlist_t *el = envlist_create();
+
+ /* NULL list */
+ g_assert_cmpint(envlist_setenv(NULL, "A=1"), ==, EINVAL);
+ g_assert_cmpint(envlist_unsetenv(NULL, "A"), ==, EINVAL);
+
+ /* NULL string */
+ g_assert_cmpint(envlist_setenv(el, NULL), ==, EINVAL);
+ g_assert_cmpint(envlist_unsetenv(el, NULL), ==, EINVAL);
+
+ /* setenv: missing '=' */
+ g_assert_cmpint(envlist_setenv(el, "NOEQ"), ==, EINVAL);
+
+ /* unsetenv: name must not contain '=' */
+ g_assert_cmpint(envlist_unsetenv(el, "A=B"), ==, EINVAL);
+
+ envlist_free(el);
+}
+
+/*
+ * Regression: envlist_unsetenv("FOO") must not remove an entry named
+ * "FOOBAR" -- the previous strncmp(entry, name, strlen(name)) lookup
+ * prefix-matched. To trigger the bug, the longer-named entry has to
+ * be ahead of the target in the list: envlist_setenv() inserts at
+ * the head, so we add FOO first and FOOBAR last.
+ */
+static void test_envlist_unsetenv_no_prefix_match(void)
+{
+ envlist_t *el = envlist_create();
+ char **env;
+ size_t count;
+
+ g_assert_cmpint(envlist_setenv(el, "FOO=y"), ==, 0);
+ g_assert_cmpint(envlist_setenv(el, "FOOBAR=x"), ==, 0);
+
+ g_assert_cmpint(envlist_unsetenv(el, "FOO"), ==, 0);
+
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 1);
+ g_assert_cmpstr(find_env(env, "FOOBAR"), ==, "x");
+ g_assert_null(find_env(env, "FOO"));
+
+ free_environ(env);
+ envlist_free(el);
+}
+
+/*
+ * envlist_setenv() must not replace a prior FOOBAR=... entry when
+ * setting FOO=... The pre-fix code happened to be safe here only
+ * because it included the trailing '=' byte in its strncmp length;
+ * this test pins down the post-fix contract that the name boundary
+ * is a property of the entry, not of the encoded form.
+ */
+static void test_envlist_setenv_no_prefix_match(void)
+{
+ envlist_t *el = envlist_create();
+ char **env;
+ size_t count;
+
+ g_assert_cmpint(envlist_setenv(el, "FOOBAR=x"), ==, 0);
+ g_assert_cmpint(envlist_setenv(el, "FOO=y"), ==, 0);
+
+ env = envlist_to_environ(el, &count);
+ g_assert_cmpuint(count, ==, 2);
+ g_assert_cmpstr(find_env(env, "FOOBAR"), ==, "x");
+ g_assert_cmpstr(find_env(env, "FOO"), ==, "y");
+
+ free_environ(env);
+ envlist_free(el);
+}
+
+int main(int argc, char *argv[])
+{
+ g_test_init(&argc, &argv, NULL);
+
+ g_test_add_func("/envlist/basic", test_envlist_basic);
+ g_test_add_func("/envlist/head_insertion_order",
+ test_envlist_head_insertion_order);
+ g_test_add_func("/envlist/einval", test_envlist_einval);
+ g_test_add_func("/envlist/unsetenv_no_prefix_match",
+ test_envlist_unsetenv_no_prefix_match);
+ g_test_add_func("/envlist/setenv_no_prefix_match",
+ test_envlist_setenv_no_prefix_match);
+
+ return g_test_run();
+}
--
2.51.0
