Stash the environment pointer we get from realloc() instead of just

setting a flag.  That way when we are called again we can be sure
to realloc() the right thing, regardless of the current value of
environ.  When the stashed value != environ (or when we are called
for the first time), copy the existing entries from environ and set
environ to the new value.  OK deraadt@, beck@, djm@

1 files changed, 24 insertions, 32 deletions

diff --git a/src/lib/libc/stdlib/setenv.c b/src/lib/libc/stdlib/setenv.c
index 2ba072b65c..40305dbe1c 100644
--- a/src/lib/libc/stdlib/setenv.c
+++ b/src/lib/libc/stdlib/setenv.c
@@ -28,7 +28,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: setenv.c,v 1.6 2003/06/02 20:18:38 millert Exp $";
+static char *rcsid = "$OpenBSD: setenv.c,v 1.7 2005/02/16 21:20:22 millert Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <stdlib.h>
@@ -36,6 +36,8 @@ static char *rcsid = "$OpenBSD: setenv.c,v 1.6 2003/06/02 20:18:38 millert Exp $
 
 char *__findenv(const char *name, int *offset);
 
+extern char **environ;
+
 /*
  * setenv --
  *      Set the value of the environmental variable "name" to be
@@ -43,13 +45,12 @@ char *__findenv(const char *name, int *offset);
  */
 int
 setenv(name, value, rewrite)
-        register const char *name;
-        register const char *value;
+        const char *name;
+        const char *value;
         int rewrite;
 {
-        extern char **environ;
-        static int alloced;                     /* if allocated space before */
-        register char *C;
+        static char **lastenv;                  /* last value of environ */
+        char *C;
         int l_value, offset;
 
         if (*value == '=')                      /* no `=' in value */
@@ -64,30 +65,23 @@ setenv(name, value, rewrite)
                         return (0);
                 }
         } else {                                        /* create new slot */
-                register int    cnt;
-                register char   **P;
+                size_t cnt;
+                char **P;
 
-                for (P = environ, cnt = 0; *P; ++P, ++cnt);
-                if (alloced) {                  /* just increase size */
-                        P = (char **)realloc((void *)environ,
-                            (size_t)(sizeof(char *) * (cnt + 2)));
-                        if (!P)
-                                return (-1);
-                        environ = P;
-                }
-                else {                          /* get new space */
-                        alloced = 1;            /* copy old entries into it */
-                        P = (char **)malloc((size_t)(sizeof(char *) *
-                            (cnt + 2)));
-                        if (!P)
-                                return (-1);
-                        bcopy(environ, P, cnt * sizeof(char *));
-                        environ = P;
-                }
-                environ[cnt + 1] = NULL;
+                for (P = environ; *P != NULL; P++)
+                        ;
+                cnt = P - environ;
+                P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
+                if (!P)
+                        return (-1);
+                if (lastenv != environ)
+                        memcpy(P, environ, cnt * sizeof(char *));
+                lastenv = environ = P;
                 offset = cnt;
+                environ[cnt + 1] = NULL;
         }
-        for (C = (char *)name; *C && *C != '='; ++C);   /* no `=' in name */
+        for (C = (char *)name; *C && *C != '='; ++C)
+                ;                               /* no `=' in name */
         if (!(environ[offset] =                 /* name + `=' + value */
             malloc((size_t)((int)(C - name) + l_value + 2))))
                 return (-1);
@@ -104,14 +98,12 @@ setenv(name, value, rewrite)
  */
 void
 unsetenv(name)
-        const char      *name;
+        const char *name;
 {
-        extern char **environ;
-        register char **P;
+        char **P;
         int offset;
-        char *__findenv();
 
-        while (__findenv(name, &offset))                /* if set multiple times */
+        while (__findenv(name, &offset))        /* if set multiple times */
                 for (P = &environ[offset];; ++P)
                         if (!(*P = *(P + 1)))
                                 break;