tests/unit: add test-envlist covering setenv/unsetenv name matching
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 <den@openvz.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20260520212628.479772-3-den@openvz.org Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Denis V. Lunev committed
May 20, 2026 at 23:26 UTC
05221c600a5f3ef657d71aeaea632c5f1bab3a2d
2 files changed
+197
tests/unit/meson.build
+1
@@ -49,6 +49,7 @@ tests = {
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'test-qapi-util': [],
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'test-interval-tree': [],
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'test-fifo': [],
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+ 'test-envlist': [],
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}
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if have_system or have_tools
tests/unit/test-envlist.c
new
+196
@@ -0,0 +1,196 @@
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
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+/*
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+ * envlist tests
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+ *
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+ * Copyright 2026 Virtuozzo International GmbH
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+ *
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+ * Authors:
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+ * Denis V. Lunev <den@openvz.org>
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+ */
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+
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+#include "qemu/osdep.h"
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+#include "qemu/envlist.h"
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+
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+static void free_environ(char **env)
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+{
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+ char **p;
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+
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+ for (p = env; *p != NULL; p++) {
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+ g_free(*p);
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+ }
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+ g_free(env);
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+}
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+
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+static const char *find_env(char **env, const char *name)
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+{
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+ size_t name_len = strlen(name);
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+ char **p;
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+
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+ for (p = env; *p != NULL; p++) {
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+ if (strncmp(*p, name, name_len) == 0 && (*p)[name_len] == '=') {
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+ return *p + name_len + 1;
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+ }
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+ }
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+ return NULL;
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+}
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+
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+static void test_envlist_basic(void)
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+{
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+ envlist_t *el = envlist_create();
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+ char **env;
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+ size_t count;
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+
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+ /* empty list */
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 0);
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+ g_assert_null(env[0]);
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+ free_environ(env);
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+
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+ /* add */
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+ g_assert_cmpint(envlist_setenv(el, "A=1"), ==, 0);
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+ g_assert_cmpint(envlist_setenv(el, "B=2"), ==, 0);
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+
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 2);
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+ g_assert_cmpstr(find_env(env, "A"), ==, "1");
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+ g_assert_cmpstr(find_env(env, "B"), ==, "2");
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+ free_environ(env);
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+
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+ /* replace */
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+ g_assert_cmpint(envlist_setenv(el, "A=42"), ==, 0);
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 2);
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+ g_assert_cmpstr(find_env(env, "A"), ==, "42");
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+ g_assert_cmpstr(find_env(env, "B"), ==, "2");
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+ free_environ(env);
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+
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+ /* unset existing */
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+ g_assert_cmpint(envlist_unsetenv(el, "A"), ==, 0);
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 1);
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+ g_assert_null(find_env(env, "A"));
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+ g_assert_cmpstr(find_env(env, "B"), ==, "2");
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+ free_environ(env);
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+
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+ /* unset non-existing is a no-op success */
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+ g_assert_cmpint(envlist_unsetenv(el, "NOPE"), ==, 0);
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 1);
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+ free_environ(env);
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+
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+ envlist_free(el);
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+}
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+
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+/*
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+ * envlist_setenv() inserts at the head; envlist_to_environ() walks
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+ * head-to-tail, so the last setenv comes out first.
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+ */
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+static void test_envlist_head_insertion_order(void)
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+{
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+ envlist_t *el = envlist_create();
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+ char **env;
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+ size_t count;
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+
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+ g_assert_cmpint(envlist_setenv(el, "A=1"), ==, 0);
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+ g_assert_cmpint(envlist_setenv(el, "B=2"), ==, 0);
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+ g_assert_cmpint(envlist_setenv(el, "C=3"), ==, 0);
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+
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 3);
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+ g_assert_cmpstr(env[0], ==, "C=3");
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+ g_assert_cmpstr(env[1], ==, "B=2");
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+ g_assert_cmpstr(env[2], ==, "A=1");
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+ g_assert_null(env[3]);
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+
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+ free_environ(env);
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+ envlist_free(el);
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+}
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+
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+static void test_envlist_einval(void)
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+{
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+ envlist_t *el = envlist_create();
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+
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+ /* NULL list */
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+ g_assert_cmpint(envlist_setenv(NULL, "A=1"), ==, EINVAL);
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+ g_assert_cmpint(envlist_unsetenv(NULL, "A"), ==, EINVAL);
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+
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+ /* NULL string */
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+ g_assert_cmpint(envlist_setenv(el, NULL), ==, EINVAL);
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+ g_assert_cmpint(envlist_unsetenv(el, NULL), ==, EINVAL);
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+
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+ /* setenv: missing '=' */
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+ g_assert_cmpint(envlist_setenv(el, "NOEQ"), ==, EINVAL);
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+
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+ /* unsetenv: name must not contain '=' */
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+ g_assert_cmpint(envlist_unsetenv(el, "A=B"), ==, EINVAL);
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+
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+ envlist_free(el);
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+}
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+
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+/*
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+ * Regression: envlist_unsetenv("FOO") must not remove an entry named
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+ * "FOOBAR" -- the previous strncmp(entry, name, strlen(name)) lookup
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+ * prefix-matched. To trigger the bug, the longer-named entry has to
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+ * be ahead of the target in the list: envlist_setenv() inserts at
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+ * the head, so we add FOO first and FOOBAR last.
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+ */
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+static void test_envlist_unsetenv_no_prefix_match(void)
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+{
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+ envlist_t *el = envlist_create();
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+ char **env;
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+ size_t count;
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+
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+ g_assert_cmpint(envlist_setenv(el, "FOO=y"), ==, 0);
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+ g_assert_cmpint(envlist_setenv(el, "FOOBAR=x"), ==, 0);
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+
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+ g_assert_cmpint(envlist_unsetenv(el, "FOO"), ==, 0);
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+
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 1);
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+ g_assert_cmpstr(find_env(env, "FOOBAR"), ==, "x");
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+ g_assert_null(find_env(env, "FOO"));
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+
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+ free_environ(env);
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+ envlist_free(el);
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+}
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+
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+/*
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+ * envlist_setenv() must not replace a prior FOOBAR=... entry when
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+ * setting FOO=... The pre-fix code happened to be safe here only
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+ * because it included the trailing '=' byte in its strncmp length;
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+ * this test pins down the post-fix contract that the name boundary
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+ * is a property of the entry, not of the encoded form.
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+ */
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+static void test_envlist_setenv_no_prefix_match(void)
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+{
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+ envlist_t *el = envlist_create();
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+ char **env;
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+ size_t count;
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+
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+ g_assert_cmpint(envlist_setenv(el, "FOOBAR=x"), ==, 0);
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+ g_assert_cmpint(envlist_setenv(el, "FOO=y"), ==, 0);
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+
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+ env = envlist_to_environ(el, &count);
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+ g_assert_cmpuint(count, ==, 2);
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+ g_assert_cmpstr(find_env(env, "FOOBAR"), ==, "x");
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+ g_assert_cmpstr(find_env(env, "FOO"), ==, "y");
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+
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+ free_environ(env);
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+ envlist_free(el);
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+}
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+
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+int main(int argc, char *argv[])
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+{
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+ g_test_init(&argc, &argv, NULL);
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+
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+ g_test_add_func("/envlist/basic", test_envlist_basic);
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+ g_test_add_func("/envlist/head_insertion_order",
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+ test_envlist_head_insertion_order);
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+ g_test_add_func("/envlist/einval", test_envlist_einval);
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+ g_test_add_func("/envlist/unsetenv_no_prefix_match",
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+ test_envlist_unsetenv_no_prefix_match);
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+ g_test_add_func("/envlist/setenv_no_prefix_match",
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+ test_envlist_setenv_no_prefix_match);
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+
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+ return g_test_run();
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+}