Changed the win32 part of this function to be thread safe and to make the

2000-04-19  Sebastian Wilhelmi  <wilhelmi@ira.uka.de>

	* gutils.c (g_getenv): Changed the win32 part of this function to
	be thread safe and to make the returned environment string
	persistent to match the UN*X behavior. This is again a response to
	Bug #8983.

	* glib.h (G_LOCK_NAME): Removed parentheses around the lock name,
	as that seems to cause problems for some compilers and really
	isn't necessary.

2 files changed, 56 insertions, 23 deletions

diff --git a/glib/glib.h b/glib/glib.h
index a371ec061..6c13c11b2 100644
--- a/glib/glib.h
+++ b/glib/glib.h
@@ -3130,7 +3130,7 @@ void      g_static_rw_lock_free (GStaticRWLock* lock);
  * G_TRYLOCK() respectively.  
  */
 extern void glib_dummy_decl (void);
-#define G_LOCK_NAME(name)		(g__ ## name ## _lock)
+#define G_LOCK_NAME(name)		g__ ## name ## _lock
 #ifdef	G_THREADS_ENABLED
 #  define G_LOCK_DEFINE_STATIC(name)	static G_LOCK_DEFINE (name)
 #  define G_LOCK_DEFINE(name)		\
diff --git a/glib/gutils.c b/glib/gutils.c
index 30c3bb755..7e99bb0b6 100644
--- a/glib/gutils.c
+++ b/glib/gutils.c
@@ -379,38 +379,71 @@ g_getenv (const gchar *variable)
 
   return getenv (variable);
 #else
-  gchar *v;
-  guint k;
-  static gchar *p = NULL;
-  static gint l;
+  G_LOCK_DEFINE_STATIC (getenv);
+  struct env_struct
+  {
+    gchar *key;
+    gchar *value;
+  } *env;
+  static GArray *environs = NULL;
+  gchar *system_env;
+  guint length, i;
   gchar dummy[2];
 
   g_return_val_if_fail (variable != NULL, NULL);
   
-  v = getenv (variable);
-  if (!v)
-    return NULL;
-  
-  /* On Windows NT, it is relatively typical that environment variables
-   * contain references to other environment variables. Handle that by
-   * calling ExpandEnvironmentStrings.
+  G_LOCK (getenv);
+
+  if (!environs)
+    environs = g_array_new (FALSE, FALSE, sizeof (struct env_struct));
+
+  /* First we try to find the envinronment variable inside the already
+   * found ones.
    */
 
-  /* First check how much space we need */
-  k = ExpandEnvironmentStrings (v, dummy, 2);
-  /* Then allocate that much, and actualy do the expansion */
-  if (p == NULL)
+  for (i = 0; i < environs->len; i++)
     {
-      p = g_malloc (k);
-      l = k;
+      env = &g_array_index (environs, struct env_struct, i);
+      if (strcmp (env->key, variable) == 0)
+	{
+	  g_assert (env->value);
+	  G_UNLOCK (getenv);
+	  return env->value;
+	}
     }
-  else if (k > l)
+
+  /* If not found, we ask the system */
+
+  system_env = getenv (variable);
+  if (!system_env)
     {
-      p = g_realloc (p, k);
-      l = k;
+      G_UNLOCK (getenv);
+      return NULL;
     }
-  ExpandEnvironmentStrings (v, p, k);
-  return p;
+
+  /* On Windows NT, it is relatively typical that environment variables
+   * contain references to other environment variables. Handle that by
+   * calling ExpandEnvironmentStrings.
+   */
+
+  g_array_set_size (environs, environs->len + 1);
+
+  env = &g_array_index (environs, struct env_struct, environs->len - 1);
+
+  /* First check how much space we need */
+  length = ExpandEnvironmentStrings (system_env, dummy, 2);
+
+  /* Then allocate that much, and actualy do the expansion and insert
+   * the new found pair into our buffer 
+   */
+
+  env->value = g_malloc (length);
+  env->key = g_strdup (variable);
+
+  ExpandEnvironmentStrings (system_env, env->value, length);
+
+  G_UNLOCK (getenv);
+  return env->value;
 #endif
 }