From 074a75bbe13fdb7faafc4f38a236385e00fe2f05 Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Mon, 5 Mar 2012 22:26:00 +0100
Subject: [PATCH] Introduce x_unsetenv for increased portability

---
 ccache.c         | 5 ++---
 ccache.h         | 1 +
 configure.ac     | 1 +
 test/test_conf.c | 2 +-
 util.c           | 9 +++++++++
 5 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/ccache.c b/ccache.c
index da67f2e6e..69b814c95 100644
--- a/ccache.c
+++ b/ccache.c
@@ -566,9 +566,8 @@ to_cache(struct args *args)
 	 * otherwise it will emit a line like
 	 *
 	 *  tmp.stdout.vexed.732.o: /home/mbp/.ccache/tmp.stdout.vexed.732.i
-	 *
-	 * unsetenv() is on BSD and Linux but not portable. */
-	putenv("DEPENDENCIES_OUTPUT");
+	 */
+	x_unsetenv("DEPENDENCIES_OUTPUT");
 
 	if (conf->run_second_cpp) {
 		args_add(args, input_file);
diff --git a/ccache.h b/ccache.h
index 6e9b8106c..53788e52f 100644
--- a/ccache.h
+++ b/ccache.h
@@ -123,6 +123,7 @@ char *x_strndup(const char *s, size_t n);
 void *x_malloc(size_t size);
 void *x_calloc(size_t nmemb, size_t size);
 void *x_realloc(void *ptr, size_t size);
+int x_unsetenv(const char *name);
 void traverse(const char *dir, void (*fn)(const char *, struct stat *));
 char *basename(const char *path);
 char *dirname(const char *path);
diff --git a/configure.ac b/configure.ac
index 64ba35ebd..35f1d9a0e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -48,6 +48,7 @@ AC_CHECK_FUNCS(mkstemp)
 AC_CHECK_FUNCS(realpath)
 AC_CHECK_FUNCS(strndup)
 AC_CHECK_FUNCS(strtok_r)
+AC_CHECK_FUNCS(unsetenv)
 AC_CHECK_FUNCS(utimes)
 
 AC_CACHE_CHECK([for compar_fn_t in stdlib.h],ccache_cv_COMPAR_FN_T, [
diff --git a/test/test_conf.c b/test/test_conf.c
index 711458a3a..802974f4d 100644
--- a/test/test_conf.c
+++ b/test/test_conf.c
@@ -307,7 +307,7 @@ TEST(conf_update_from_environment)
 	CHECK(conf_update_from_environment(conf, &errmsg));
 	CHECK(conf->compression);
 
-	putenv("CCACHE_COMPRESS"); /* unsetenv isn't portable */
+	x_unsetenv("CCACHE_COMPRESS");
 	putenv("CCACHE_NOCOMPRESS=1");
 	CHECK(conf_update_from_environment(conf, &errmsg));
 	CHECK(!conf->compression);
diff --git a/util.c b/util.c
index db39a120e..1d473ac5e 100644
--- a/util.c
+++ b/util.c
@@ -679,6 +679,15 @@ x_realloc(void *ptr, size_t size)
 	return p2;
 }
 
+/* This is like unsetenv. */
+int x_unsetenv(const char *name)
+{
+#ifdef HAVE_UNSETENV
+	return unsetenv(name);
+#else
+	return putenv(x_strdup(name)); /* Leak to environment. */
+#endif
+}
 
 /*
  * Construct a string according to the format and store it in *ptr. The
-- 
2.47.3