1 files changed, 58 insertions, 19 deletions

diff --git a/sysdeps/generic/setenv.c b/sysdeps/generic/setenv.c
index 1907a2b7e1..dc2e8b43f3 100644
--- a/sysdeps/generic/setenv.c
+++ b/sysdeps/generic/setenv.c
@@ -16,24 +16,36 @@ License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
 Cambridge, MA 02139, USA.  */
 
-#include <ansidecl.h>
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <errno.h>
+
+#if _LIBC || HAVE_STDLIB_H
 #include <stdlib.h>
+#endif
+#if _LIBC || HAVE_STRING_H
 #include <string.h>
+#endif
+#if _LIBC || HAVE_UNISTD_H
 #include <unistd.h>
-#include <errno.h>
+#endif
 
 #ifndef	HAVE_GNU_LD
 #define	__environ	environ
 #endif
 
 int
-DEFUN(setenv, (name, value, replace),
-      CONST char *name AND CONST char *value AND int replace)
+setenv (name, value, replace)
+     const char *name;
+     const char *value;
+     int replace;
 {
   register char **ep;
   register size_t size;
-  CONST size_t namelen = strlen (name);
-  CONST size_t vallen = strlen (value);
+  const size_t namelen = strlen (name);
+  const size_t vallen = strlen (value) + 1;
 
   size = 0;
   for (ep = __environ; *ep != NULL; ++ep)
@@ -41,38 +53,47 @@ DEFUN(setenv, (name, value, replace),
       break;
     else
       ++size;
-  
+
   if (*ep == NULL)
     {
-      static char **last_environ = NULL;
-      char **new_environ = (char **) malloc((size + 2) * sizeof(char *));
+      static char **last_environ;
+      char **new_environ;
+      if (__environ == last_environ)
+	/* We allocated this space; we can extend it.  */
+	new_environ = (char **) realloc (last_environ,
+					 (size + 2) * sizeof (char *));
+      else
+	new_environ = (char **) malloc ((size + 2) * sizeof (char *));
+
       if (new_environ == NULL)
 	return -1;
-      (void) memcpy((PTR) new_environ, (PTR) __environ, size * sizeof(char *));
 
-      new_environ[size] = malloc (namelen + 1 + vallen + 1);
+      new_environ[size] = malloc (namelen + 1 + vallen);
       if (new_environ[size] == NULL)
 	{
-	  free (new_environ);
+	  free ((char *) new_environ);
 	  errno = ENOMEM;
 	  return -1;
 	}
+
+      if (__environ != last_environ)
+	memcpy ((char *) new_environ, (char *) __environ,
+		size * sizeof (char *));
+
       memcpy (new_environ[size], name, namelen);
       new_environ[size][namelen] = '=';
-      memcpy (&new_environ[size][namelen + 1], value, vallen + 1);
+      memcpy (&new_environ[size][namelen + 1], value, vallen);
 
       new_environ[size + 1] = NULL;
 
-      if (last_environ != NULL)
-	free ((PTR) last_environ);
-      last_environ = new_environ;
-      __environ = new_environ;
+      last_environ = __environ = new_environ;
     }
   else if (replace)
     {
       size_t len = strlen (*ep);
-      if (len < namelen + 1 + vallen)
+      if (len + 1 < namelen + 1 + vallen)
 	{
+	  /* The existing string is too short; malloc a new one.  */
 	  char *new = malloc (namelen + 1 + vallen);
 	  if (new == NULL)
 	    return -1;
@@ -80,8 +101,26 @@ DEFUN(setenv, (name, value, replace),
 	}
       memcpy (*ep, name, namelen);
       (*ep)[namelen] = '=';
-      memcpy (&(*ep)[namelen + 1], value, vallen + 1);
+      memcpy (&(*ep)[namelen + 1], value, vallen);
     }
 
   return 0;
 }
+
+void
+unsetenv (const char *name)
+{
+  const size_t len = strlen (name);
+  char **ep;
+
+  for (ep = __environ; *ep; ++ep)
+    if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
+      {
+	/* Found it.  Remove this pointer by moving later ones back.  */
+	char **dp = ep;
+	do
+	  dp[0] = dp[1];
+	while (*dp++);
+	/* Continue the loop in case NAME appears again.  */
+      }
+}