* Clean up some function definitions to comply with strict

     prototypes. Suggested and worked in part by Holger Hoffstätte.

75 files changed, 158 insertions, 14 deletions

diff --git a/imap/src/osdep/amiga/dummy.c b/imap/src/osdep/amiga/dummy.c
index cb3b45bd..b33297e8 100644
--- a/imap/src/osdep/amiga/dummy.c
+++ b/imap/src/osdep/amiga/dummy.c
@@ -27,7 +27,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/amiga/mbx.c b/imap/src/osdep/amiga/mbx.c
index 3cc89c94..bf3aa0ac 100644
--- a/imap/src/osdep/amiga/mbx.c
+++ b/imap/src/osdep/amiga/mbx.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/amiga/mh.c b/imap/src/osdep/amiga/mh.c
index a7b56e8c..02bb917c 100644
--- a/imap/src/osdep/amiga/mh.c
+++ b/imap/src/osdep/amiga/mh.c
@@ -27,7 +27,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/amiga/mix.c b/imap/src/osdep/amiga/mix.c
index 9ab3442c..9c5ad9da 100644
--- a/imap/src/osdep/amiga/mix.c
+++ b/imap/src/osdep/amiga/mix.c
@@ -26,7 +26,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/amiga/mmdf.c b/imap/src/osdep/amiga/mmdf.c
index e962434e..8e26a6c1 100644
--- a/imap/src/osdep/amiga/mmdf.c
+++ b/imap/src/osdep/amiga/mmdf.c
@@ -28,7 +28,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <signal.h>
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/amiga/mtx.c b/imap/src/osdep/amiga/mtx.c
index 4c989564..1502b86c 100644
--- a/imap/src/osdep/amiga/mtx.c
+++ b/imap/src/osdep/amiga/mtx.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/amiga/mx.c b/imap/src/osdep/amiga/mx.c
index 7e2b022e..f2d6b3d3 100644
--- a/imap/src/osdep/amiga/mx.c
+++ b/imap/src/osdep/amiga/mx.c
@@ -30,7 +30,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/amiga/news.c b/imap/src/osdep/amiga/news.c
index 9c9f738a..34ad6b45 100644
--- a/imap/src/osdep/amiga/news.c
+++ b/imap/src/osdep/amiga/news.c
@@ -30,7 +30,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <sys/stat.h>
diff --git a/imap/src/osdep/amiga/os_ami.c b/imap/src/osdep/amiga/os_ami.c
index 9f0d27b0..90d611cc 100644
--- a/imap/src/osdep/amiga/os_ami.c
+++ b/imap/src/osdep/amiga/os_ami.c
@@ -39,7 +39,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/amiga/phile.c b/imap/src/osdep/amiga/phile.c
index ce72d0a9..e01eec22 100644
--- a/imap/src/osdep/amiga/phile.c
+++ b/imap/src/osdep/amiga/phile.c
@@ -30,7 +30,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <signal.h>
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/amiga/tenex.c b/imap/src/osdep/amiga/tenex.c
index 0982573f..c3f95e5a 100644
--- a/imap/src/osdep/amiga/tenex.c
+++ b/imap/src/osdep/amiga/tenex.c
@@ -42,7 +42,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <sys/stat.h>
diff --git a/imap/src/osdep/amiga/unix.c b/imap/src/osdep/amiga/unix.c
index be3c437b..e553662f 100644
--- a/imap/src/osdep/amiga/unix.c
+++ b/imap/src/osdep/amiga/unix.c
@@ -40,7 +40,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <signal.h>
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/nt/mbxnt.c b/imap/src/osdep/nt/mbxnt.c
index f35bfa6c..859d06ea 100644
--- a/imap/src/osdep/nt/mbxnt.c
+++ b/imap/src/osdep/nt/mbxnt.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <fcntl.h>
diff --git a/imap/src/osdep/nt/mtxnt.c b/imap/src/osdep/nt/mtxnt.c
index fa80afde..90e7927e 100644
--- a/imap/src/osdep/nt/mtxnt.c
+++ b/imap/src/osdep/nt/mtxnt.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <fcntl.h>
diff --git a/imap/src/osdep/nt/tenexnt.c b/imap/src/osdep/nt/tenexnt.c
index 054ce73a..c1c57946 100644
--- a/imap/src/osdep/nt/tenexnt.c
+++ b/imap/src/osdep/nt/tenexnt.c
@@ -42,7 +42,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <fcntl.h>
diff --git a/imap/src/osdep/nt/unixnt.c b/imap/src/osdep/nt/unixnt.c
index 8c147985..1b9ee3a2 100644
--- a/imap/src/osdep/nt/unixnt.c
+++ b/imap/src/osdep/nt/unixnt.c
@@ -40,7 +40,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <time.h>
diff --git a/imap/src/osdep/os2/mbxnt.c b/imap/src/osdep/os2/mbxnt.c
index 5ea3b57e..44276adc 100644
--- a/imap/src/osdep/os2/mbxnt.c
+++ b/imap/src/osdep/os2/mbxnt.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <fcntl.h>
diff --git a/imap/src/osdep/os2/mtxnt.c b/imap/src/osdep/os2/mtxnt.c
index 0ca88fb7..7a4d0440 100644
--- a/imap/src/osdep/os2/mtxnt.c
+++ b/imap/src/osdep/os2/mtxnt.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <fcntl.h>
diff --git a/imap/src/osdep/os2/os_os2.c b/imap/src/osdep/os2/os_os2.c
index 9c6f2f5f..172b33e8 100644
--- a/imap/src/osdep/os2/os_os2.c
+++ b/imap/src/osdep/os2/os_os2.c
@@ -37,7 +37,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "tcp_os2.h"		/* must be before osdep includes tcp.h */
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/os2/tenexnt.c b/imap/src/osdep/os2/tenexnt.c
index 4c1d0a3b..4609bfd8 100644
--- a/imap/src/osdep/os2/tenexnt.c
+++ b/imap/src/osdep/os2/tenexnt.c
@@ -42,7 +42,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <fcntl.h>
diff --git a/imap/src/osdep/os2/unixnt.c b/imap/src/osdep/os2/unixnt.c
index 2e92d39a..0bf45ca2 100644
--- a/imap/src/osdep/os2/unixnt.c
+++ b/imap/src/osdep/os2/unixnt.c
@@ -40,7 +40,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <time.h>
diff --git a/imap/src/osdep/unix/dummy.c b/imap/src/osdep/unix/dummy.c
index 646f67ea..992d855e 100644
--- a/imap/src/osdep/unix/dummy.c
+++ b/imap/src/osdep/unix/dummy.c
@@ -27,7 +27,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/env_unix.c b/imap/src/osdep/unix/env_unix.c
index c41a5d04..c2fae370 100644
--- a/imap/src/osdep/unix/env_unix.c
+++ b/imap/src/osdep/unix/env_unix.c
@@ -967,7 +967,7 @@ char *myusername_full (unsigned long *flags)
  * Returns: my local host name
  */
 
-char *mylocalhost ()
+char *mylocalhost (void)
 {
   if (!myLocalHost) {
     char *s,tmp[MAILTMPLEN];
@@ -985,7 +985,7 @@ char *mylocalhost ()
  * Returns: my home directory name
  */
 
-char *myhomedir ()
+char *myhomedir (void)
 {
   if (!myHomeDir) myusername ();/* initialize if first time */
   return myHomeDir ? myHomeDir : "";
@@ -996,7 +996,7 @@ char *myhomedir ()
  * Returns: my home directory name
  */
 
-static char *mymailboxdir ()
+static char *mymailboxdir (void)
 {
   char *home = myhomedir ();
 				/* initialize if first time */
@@ -1016,7 +1016,7 @@ static char *mymailboxdir ()
  * Accepts: buffer string
  */
 
-char *sysinbox ()
+char *sysinbox (void)
 {
   char tmp[MAILTMPLEN];
   if (!sysInbox) {		/* initialize if first time */
diff --git a/imap/src/osdep/unix/kerb_mit.c b/imap/src/osdep/unix/kerb_mit.c
index 82e6c936..f4b4e5ed 100644
--- a/imap/src/osdep/unix/kerb_mit.c
+++ b/imap/src/osdep/unix/kerb_mit.c
@@ -42,7 +42,7 @@ char *kerberos_login (char *user,char *authuser,int argc,char *argv[]);
  * This is alright since the server is probably still root at this point.
  */
 
-long kerberos_server_valid ()
+long kerberos_server_valid (void)
 {
   krb5_context ctx;
   krb5_keytab kt;
diff --git a/imap/src/osdep/unix/mbx.c b/imap/src/osdep/unix/mbx.c
index 3770e0a9..48a555be 100644
--- a/imap/src/osdep/unix/mbx.c
+++ b/imap/src/osdep/unix/mbx.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/mh.c b/imap/src/osdep/unix/mh.c
index 68e3aa68..565332d5 100644
--- a/imap/src/osdep/unix/mh.c
+++ b/imap/src/osdep/unix/mh.c
@@ -27,7 +27,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/mix.c b/imap/src/osdep/unix/mix.c
index 11b4b3a3..dc7981d3 100644
--- a/imap/src/osdep/unix/mix.c
+++ b/imap/src/osdep/unix/mix.c
@@ -26,7 +26,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/mmdf.c b/imap/src/osdep/unix/mmdf.c
index 5cfa197e..70196144 100644
--- a/imap/src/osdep/unix/mmdf.c
+++ b/imap/src/osdep/unix/mmdf.c
@@ -28,7 +28,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <signal.h>
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/unix/mtx.c b/imap/src/osdep/unix/mtx.c
index 0afa3376..d2257313 100644
--- a/imap/src/osdep/unix/mtx.c
+++ b/imap/src/osdep/unix/mtx.c
@@ -37,7 +37,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/mx.c b/imap/src/osdep/unix/mx.c
index 6ba04ca0..274f88fe 100644
--- a/imap/src/osdep/unix/mx.c
+++ b/imap/src/osdep/unix/mx.c
@@ -30,7 +30,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/news.c b/imap/src/osdep/unix/news.c
index beda8a66..a733d576 100644
--- a/imap/src/osdep/unix/news.c
+++ b/imap/src/osdep/unix/news.c
@@ -30,7 +30,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <sys/stat.h>
diff --git a/imap/src/osdep/unix/os_a32.c b/imap/src/osdep/unix/os_a32.c
index 513e92c7..4c63bf39 100644
--- a/imap/src/osdep/unix/os_a32.c
+++ b/imap/src/osdep/unix/os_a32.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 #include <sys/select.h>
diff --git a/imap/src/osdep/unix/os_a41.c b/imap/src/osdep/unix/os_a41.c
index ecaff582..c7e66d35 100644
--- a/imap/src/osdep/unix/os_a41.c
+++ b/imap/src/osdep/unix/os_a41.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 #include <sys/select.h>
diff --git a/imap/src/osdep/unix/os_a52.c b/imap/src/osdep/unix/os_a52.c
index fed6af78..396ddc6f 100644
--- a/imap/src/osdep/unix/os_a52.c
+++ b/imap/src/osdep/unix/os_a52.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 #include <sys/select.h>
diff --git a/imap/src/osdep/unix/os_aix.c b/imap/src/osdep/unix/os_aix.c
index c38e5cf9..8ea809b4 100644
--- a/imap/src/osdep/unix/os_aix.c
+++ b/imap/src/osdep/unix/os_aix.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_aos.c b/imap/src/osdep/unix/os_aos.c
index a916f47b..96bc5fea 100644
--- a/imap/src/osdep/unix/os_aos.c
+++ b/imap/src/osdep/unix/os_aos.c
@@ -37,7 +37,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_art.c b/imap/src/osdep/unix/os_art.c
index 8fb78028..f3111c01 100644
--- a/imap/src/osdep/unix/os_art.c
+++ b/imap/src/osdep/unix/os_art.c
@@ -36,7 +36,9 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <errno.h>
-extern int errno;
+#ifndef errno
+extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <sys/socket.h>
 #include <time.h>
diff --git a/imap/src/osdep/unix/os_aux.h b/imap/src/osdep/unix/os_aux.h
index 53ec6cc5..304e996f 100644
--- a/imap/src/osdep/unix/os_aux.h
+++ b/imap/src/osdep/unix/os_aux.h
@@ -37,7 +37,9 @@
 #include <syslog.h>
 
 
-extern int errno;
+#ifndef errno
+extern int errno;		/* just in case */
+#endif
 
 char *strerror (int n);
 unsigned long strtoul (char *s,char **endp,int base);
diff --git a/imap/src/osdep/unix/os_bsd.c b/imap/src/osdep/unix/os_bsd.c
index a916f47b..96bc5fea 100644
--- a/imap/src/osdep/unix/os_bsd.c
+++ b/imap/src/osdep/unix/os_bsd.c
@@ -37,7 +37,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_bsf.c b/imap/src/osdep/unix/os_bsf.c
index f32b1fb2..ee66ca2f 100644
--- a/imap/src/osdep/unix/os_bsf.c
+++ b/imap/src/osdep/unix/os_bsf.c
@@ -35,7 +35,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_bsi.c b/imap/src/osdep/unix/os_bsi.c
index f32b1fb2..ee66ca2f 100644
--- a/imap/src/osdep/unix/os_bsi.c
+++ b/imap/src/osdep/unix/os_bsi.c
@@ -35,7 +35,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_cvx.c b/imap/src/osdep/unix/os_cvx.c
index 10f01904..09d49815 100644
--- a/imap/src/osdep/unix/os_cvx.c
+++ b/imap/src/osdep/unix/os_cvx.c
@@ -42,7 +42,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_cyg.c b/imap/src/osdep/unix/os_cyg.c
index c9cd2f70..fc300e38 100644
--- a/imap/src/osdep/unix/os_cyg.c
+++ b/imap/src/osdep/unix/os_cyg.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <crypt.h>
 #include "misc.h"
diff --git a/imap/src/osdep/unix/os_d-g.c b/imap/src/osdep/unix/os_d-g.c
index b34662f7..96d2b579 100644
--- a/imap/src/osdep/unix/os_d-g.c
+++ b/imap/src/osdep/unix/os_d-g.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_do4.c b/imap/src/osdep/unix/os_do4.c
index 186fd94e..95da87ec 100644
--- a/imap/src/osdep/unix/os_do4.c
+++ b/imap/src/osdep/unix/os_do4.c
@@ -36,7 +36,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_drs.c b/imap/src/osdep/unix/os_drs.c
index 74386af9..35c2e35d 100644
--- a/imap/src/osdep/unix/os_drs.c
+++ b/imap/src/osdep/unix/os_drs.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_dyn.c b/imap/src/osdep/unix/os_dyn.c
index 98a1a548..dd864372 100644
--- a/imap/src/osdep/unix/os_dyn.c
+++ b/imap/src/osdep/unix/os_dyn.c
@@ -37,7 +37,9 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_hpp.c b/imap/src/osdep/unix/os_hpp.c
index 39794973..ca7f1cdc 100644
--- a/imap/src/osdep/unix/os_hpp.c
+++ b/imap/src/osdep/unix/os_hpp.c
@@ -44,7 +44,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 extern char *sys_errlist[];
 extern int sys_nerr;
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/os_lnx.c b/imap/src/osdep/unix/os_lnx.c
index e95b2ac2..0b4b3eb3 100644
--- a/imap/src/osdep/unix/os_lnx.c
+++ b/imap/src/osdep/unix/os_lnx.c
@@ -35,7 +35,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_lyn.c b/imap/src/osdep/unix/os_lyn.c
index 49871251..4e59250b 100644
--- a/imap/src/osdep/unix/os_lyn.c
+++ b/imap/src/osdep/unix/os_lyn.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_mct.c b/imap/src/osdep/unix/os_mct.c
index cb62de50..35243018 100644
--- a/imap/src/osdep/unix/os_mct.c
+++ b/imap/src/osdep/unix/os_mct.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_mnt.c b/imap/src/osdep/unix/os_mnt.c
index f19a487b..6f257149 100644
--- a/imap/src/osdep/unix/os_mnt.c
+++ b/imap/src/osdep/unix/os_mnt.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_nto.c b/imap/src/osdep/unix/os_nto.c
index 36c45b42..0dfcd833 100644
--- a/imap/src/osdep/unix/os_nto.c
+++ b/imap/src/osdep/unix/os_nto.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <shadow.h>
 #include <sys/select.h>
diff --git a/imap/src/osdep/unix/os_nxt.c b/imap/src/osdep/unix/os_nxt.c
index a3b749f5..7bb754bd 100644
--- a/imap/src/osdep/unix/os_nxt.c
+++ b/imap/src/osdep/unix/os_nxt.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_os4.c b/imap/src/osdep/unix/os_os4.c
index 42d90404..5fe1e798 100644
--- a/imap/src/osdep/unix/os_os4.c
+++ b/imap/src/osdep/unix/os_os4.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 #include <sia.h>
diff --git a/imap/src/osdep/unix/os_osf.c b/imap/src/osdep/unix/os_osf.c
index 560a3b59..9dbfa9da 100644
--- a/imap/src/osdep/unix/os_osf.c
+++ b/imap/src/osdep/unix/os_osf.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 #include <ustat.h>
diff --git a/imap/src/osdep/unix/os_osx.c b/imap/src/osdep/unix/os_osx.c
index 1788e21f..40561b7b 100644
--- a/imap/src/osdep/unix/os_osx.c
+++ b/imap/src/osdep/unix/os_osx.c
@@ -36,7 +36,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_pyr.c b/imap/src/osdep/unix/os_pyr.c
index 69c8e7e4..64c17220 100644
--- a/imap/src/osdep/unix/os_pyr.c
+++ b/imap/src/osdep/unix/os_pyr.c
@@ -41,7 +41,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_qn6.c b/imap/src/osdep/unix/os_qn6.c
index ded8c848..1ca60739 100644
--- a/imap/src/osdep/unix/os_qn6.c
+++ b/imap/src/osdep/unix/os_qn6.c
@@ -35,7 +35,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <shadow.h>
 #include <sys/select.h>
diff --git a/imap/src/osdep/unix/os_qnx.c b/imap/src/osdep/unix/os_qnx.c
index b1382519..d273545f 100644
--- a/imap/src/osdep/unix/os_qnx.c
+++ b/imap/src/osdep/unix/os_qnx.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <shadow.h>
 #include <sys/select.h>
diff --git a/imap/src/osdep/unix/os_s40.c b/imap/src/osdep/unix/os_s40.c
index 3dc2fe63..d5faec9f 100644
--- a/imap/src/osdep/unix/os_s40.c
+++ b/imap/src/osdep/unix/os_s40.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_sgi.c b/imap/src/osdep/unix/os_sgi.c
index 3e5eb550..0044b47e 100644
--- a/imap/src/osdep/unix/os_sgi.c
+++ b/imap/src/osdep/unix/os_sgi.c
@@ -39,7 +39,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_shp.c b/imap/src/osdep/unix/os_shp.c
index eb7e4e80..da657fb6 100644
--- a/imap/src/osdep/unix/os_shp.c
+++ b/imap/src/osdep/unix/os_shp.c
@@ -44,7 +44,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 extern char *sys_errlist[];
 extern int sys_nerr;
 #include <pwd.h>
diff --git a/imap/src/osdep/unix/os_slx.c b/imap/src/osdep/unix/os_slx.c
index 95c586af..5b672c33 100644
--- a/imap/src/osdep/unix/os_slx.c
+++ b/imap/src/osdep/unix/os_slx.c
@@ -35,7 +35,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <shadow.h>
 #include "misc.h"
diff --git a/imap/src/osdep/unix/os_sos.c b/imap/src/osdep/unix/os_sos.c
index 8256aafa..4f7c95a0 100644
--- a/imap/src/osdep/unix/os_sos.c
+++ b/imap/src/osdep/unix/os_sos.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 #include <sys/security.h>
diff --git a/imap/src/osdep/unix/os_sua.c b/imap/src/osdep/unix/os_sua.c
index dcf9311b..c908b9da 100644
--- a/imap/src/osdep/unix/os_sua.c
+++ b/imap/src/osdep/unix/os_sua.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_sun.c b/imap/src/osdep/unix/os_sun.c
index 5348ef58..ce7cc394 100644
--- a/imap/src/osdep/unix/os_sun.c
+++ b/imap/src/osdep/unix/os_sun.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_sv2.c b/imap/src/osdep/unix/os_sv2.c
index 14e3951b..880995ff 100644
--- a/imap/src/osdep/unix/os_sv2.c
+++ b/imap/src/osdep/unix/os_sv2.c
@@ -36,7 +36,9 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <errno.h>
-extern int errno;
+#ifndef errno
+extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include <sys/socket.h>
 #include <time.h>
diff --git a/imap/src/osdep/unix/os_ult.c b/imap/src/osdep/unix/os_ult.c
index 28b72ecc..ebcf2a0d 100644
--- a/imap/src/osdep/unix/os_ult.c
+++ b/imap/src/osdep/unix/os_ult.c
@@ -37,7 +37,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/os_vu2.c b/imap/src/osdep/unix/os_vu2.c
index 0b9c026a..2bbe4765 100644
--- a/imap/src/osdep/unix/os_vu2.c
+++ b/imap/src/osdep/unix/os_vu2.c
@@ -37,7 +37,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <pwd.h>
 #include "misc.h"
 
diff --git a/imap/src/osdep/unix/phile.c b/imap/src/osdep/unix/phile.c
index e930841b..a972f257 100644
--- a/imap/src/osdep/unix/phile.c
+++ b/imap/src/osdep/unix/phile.c
@@ -30,7 +30,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <signal.h>
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/unix/tcp_unix.c b/imap/src/osdep/unix/tcp_unix.c
index cf18bb6f..e601164c 100644
--- a/imap/src/osdep/unix/tcp_unix.c
+++ b/imap/src/osdep/unix/tcp_unix.c
@@ -838,7 +838,7 @@ char *tcp_localhost (TCPSTREAM *stream)
  * Returns: client host address
  */
 
-char *tcp_clientaddr ()
+char *tcp_clientaddr (void)
 {
   if (!myClientAddr) {
     char buf[NI_MAXHOST];
@@ -860,7 +860,7 @@ char *tcp_clientaddr ()
  * Returns: client host name
  */
 
-char *tcp_clienthost ()
+char *tcp_clienthost (void)
 {
   if (!myClientHost) {
     char buf[NI_MAXHOST];
@@ -892,7 +892,7 @@ char *tcp_clienthost ()
  * Returns: client port number
  */
 
-long tcp_clientport ()
+long tcp_clientport (void)
 {
   if (!myClientHost && !myClientAddr) tcp_clientaddr ();
   return myClientPort;
@@ -902,7 +902,7 @@ long tcp_clientport ()
  * Returns: server host address
  */
 
-char *tcp_serveraddr ()
+char *tcp_serveraddr (void)
 {
   if (!myServerAddr) {
     char buf[NI_MAXHOST];
@@ -924,7 +924,7 @@ char *tcp_serveraddr ()
  * Returns: server host name
  */
 
-char *tcp_serverhost ()
+char *tcp_serverhost (void)
 {
   if (!myServerHost) {		/* once-only */
     char buf[NI_MAXHOST];
@@ -948,7 +948,7 @@ char *tcp_serverhost ()
  * Returns: server port number
  */
 
-long tcp_serverport ()
+long tcp_serverport (void)
 {
   if (!myServerHost && !myServerAddr) tcp_serveraddr ();
   return myServerPort;
diff --git a/imap/src/osdep/unix/tenex.c b/imap/src/osdep/unix/tenex.c
index 6d8ec011..c99d4b85 100644
--- a/imap/src/osdep/unix/tenex.c
+++ b/imap/src/osdep/unix/tenex.c
@@ -42,7 +42,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "mail.h"
 #include "osdep.h"
 #include <sys/stat.h>
diff --git a/imap/src/osdep/unix/unix.c b/imap/src/osdep/unix/unix.c
index 4bbaa01a..ec8dab94 100644
--- a/imap/src/osdep/unix/unix.c
+++ b/imap/src/osdep/unix/unix.c
@@ -40,7 +40,9 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include <signal.h>
 #include "mail.h"
 #include "osdep.h"
diff --git a/imap/src/osdep/vms/os_vms.c b/imap/src/osdep/vms/os_vms.c
index cd333ba9..7e8b2c84 100644
--- a/imap/src/osdep/vms/os_vms.c
+++ b/imap/src/osdep/vms/os_vms.c
@@ -38,7 +38,9 @@
 #include <netdb.h>
 #include <ctype.h>
 #include <errno.h>
+#ifndef errno
 extern int errno;		/* just in case */
+#endif
 #include "misc.h"