call uselocale() before freelocale() to make sure that g_local_key has a valid locale.

For tests that call uselocale(), the locale is stored in the
g_userlocale_key thread-specific key. If freelocale() is called later,
then g_uselocal_key points to a deleted pointer. CTS eventually calls
vfprintf to print the result, which calls MB_CUR_MAX and MB_CUR_MAX
accesses the deleted locale stored in g_uselocale_key, causing unpredictable
errors.

Fixed the tests by calling uselocale() with the old locale before
calling freelocale.

Bug: 17299565
Change-Id: I87efa2a9b16999a11d587f68d3aeedcbe6ac8a2c

2 files changed, 4 insertions, 2 deletions

diff --git a/tests/locale_test.cpp b/tests/locale_test.cpp
index 325f6ce..7ec607a 100644
--- a/tests/locale_test.cpp
+++ b/tests/locale_test.cpp
@@ -114,11 +114,12 @@ TEST(locale, mb_cur_max) {
   locale_t cloc = newlocale(LC_ALL, "C", 0);
   locale_t cloc_utf8 = newlocale(LC_ALL, "C.UTF-8", 0);
 
-  uselocale(cloc);
+  locale_t old_locale = uselocale(cloc);
   ASSERT_EQ(1U, MB_CUR_MAX);
   uselocale(cloc_utf8);
   ASSERT_EQ(4U, MB_CUR_MAX);
 
+  uselocale(old_locale);
   freelocale(cloc);
   freelocale(cloc_utf8);
 }
diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index bb86509..8c8c235 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -428,7 +428,7 @@ TEST(stdio, snprintf_negative_zero_5084292) {
 
 TEST(stdio, snprintf_utf8_15439554) {
   locale_t cloc = newlocale(LC_ALL, "C.UTF-8", 0);
-  uselocale(cloc);
+  locale_t old_locale = uselocale(cloc);
 
   // http://b/15439554
   char buf[BUFSIZ];
@@ -446,6 +446,7 @@ TEST(stdio, snprintf_utf8_15439554) {
   snprintf(buf, sizeof(buf), "%d\xf0\xa4\xad\xa2%d", 1, 2);
   EXPECT_STREQ("1𤭢2", buf);
 
+  uselocale(old_locale);
   freelocale(cloc);
 }