Mark printf-like calls with MU_PRINTFLIKE.

@@ -66,7 +66,7 @@ void collect_create_mailbox (void);
 void collect_drop_mailbox (void);
 int collect_output (void);
 
-void util_error (char *fmt, ...);
+void util_error (char *fmt, ...) MU_PRINTFLIKE(1, 2);
 int util_tempfile (char **namep);
 
 struct guimb_data

@@ -241,12 +241,13 @@ extern void imap4d_capability_remove (const char *str);
 extern void imap4d_capability_init (void);
   
 /* Helper functions.  */
-extern int  util_out (int, const char *, ...);
-extern int  util_send (const char *, ...);
+extern int  util_out (int, const char *, ...) MU_PRINTFLIKE(2,3);
+extern int  util_send (const char *, ...) MU_PRINTFLIKE(1,2);
 extern int  util_send_qstring (const char *);
 extern int  util_send_literal (const char *);
 extern int  util_start (char *);
-extern int  util_finish (struct imap4d_command *, int, const char *, ...);
+extern int  util_finish (struct imap4d_command *, int, const char *, ...) 
+                         MU_PRINTFLIKE(3,4);
 extern int  util_getstate (void);
 extern int  util_do_command (char *);
 extern char *imap4d_readline (void);

@@ -37,7 +37,7 @@ extern void * mu_debug_get_owner (mu_debug_t);
 extern int mu_debug_set_level (mu_debug_t, size_t level);
 extern int mu_debug_get_level (mu_debug_t, size_t *plevel);
 extern int mu_debug_print     (mu_debug_t debug, size_t level,
-			       const char *format, ...);
+			       const char *format, ...) MU_PRINTFLIKE(3,4);
 extern int mu_debug_printv    (mu_debug_t debug, size_t level,
 			       const char *format, va_list argp);
 extern int mu_debug_set_print (mu_debug_t, 

@@ -30,7 +30,7 @@ extern "C" {
 typedef int (*mu_error_pfn_t) (const char *fmt, va_list ap);
 
 extern int mu_verror (const char *fmt, va_list ap);
-extern int mu_error (const char *fmt, ...);
+extern int mu_error (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 extern void mu_error_set_print (mu_error_pfn_t);
 
 int mu_default_error_printer (const char *fmt, va_list ap);

@@ -239,12 +239,16 @@ int mu_sieve_get_message_sender (mu_message_t msg, char **ptext);
 
 /* Logging and diagnostic functions */
 
-void mu_sieve_error (mu_sieve_machine_t mach, const char *fmt, ...);
-void mu_sieve_debug (mu_sieve_machine_t mach, const char *fmt, ...);
+void mu_sieve_error (mu_sieve_machine_t mach, const char *fmt, ...) 
+                     MU_PRINTFLIKE(2,3);
+void mu_sieve_debug (mu_sieve_machine_t mach, const char *fmt, ...)
+                     MU_PRINTFLIKE(2,3);
 void mu_sieve_log_action (mu_sieve_machine_t mach, const char *action,
-			  const char *fmt, ...);
+			  const char *fmt, ...)
+			  MU_PRINTFLIKE(3,4);
 void mu_sieve_abort (mu_sieve_machine_t mach);
-int mu_stream_printf (mu_stream_t stream, size_t * off, const char *fmt, ...);
+int mu_stream_printf (mu_stream_t stream, size_t * off, const char *fmt, ...)
+                      MU_PRINTFLIKE(3,4);
 void mu_sieve_arg_error (mu_sieve_machine_t mach, int n);
 
 int mu_sieve_is_dry_run (mu_sieve_machine_t mach);

@@ -229,7 +229,8 @@ extern int  mu_nntp_response     (mu_nntp_t nntp, char *buffer,
 
 /* pop3_writeline copies the line in the internal buffer, a mu_pop3_send() is
    needed to do the actual transmission.  */
-extern int  mu_nntp_writeline    (mu_nntp_t nntp, const char *format, ...);
+extern int  mu_nntp_writeline    (mu_nntp_t nntp, const char *format, ...)
+                                  MU_PRINTFLIKE(2,3);
 
 /* mu_pop3_sendline() is equivalent to:
        mu_pop3_writeline (pop3, line);

@@ -102,7 +102,8 @@ extern int  mu_pop3_response     (mu_pop3_t pop3, char *buffer, size_t buflen, s
 
 /* pop3_writeline copies the line in the internal buffer, a mu_pop3_send() is
    needed to do the actual transmission.  */
-extern int  mu_pop3_writeline    (mu_pop3_t pop3, const char *format, ...);
+extern int  mu_pop3_writeline    (mu_pop3_t pop3, const char *format, ...)
+                                  MU_PRINTFLIKE(2,3);
 
 /* mu_pop3_sendline() is equivalent to:
        mu_pop3_writeline (pop3, line);

@@ -222,7 +222,7 @@ struct _msg_imap
   size_t header_lines;
 };
 
-int imap_writeline    (f_imap_t,  const char *format, ...);
+int imap_writeline    (f_imap_t,  const char *format, ...) MU_PRINTFLIKE(2,3);
 int imap_write        (f_imap_t);
 int imap_send         (f_imap_t);
 int imap_parse        (f_imap_t);

@@ -89,9 +89,9 @@ extern int sieve_error_count;
 #define TAG_RELFUN  "__relfun__"
 
 void sieve_compile_error (const char *filename, int linenum,
-			  const char *fmt, ...);
+			  const char *fmt, ...) MU_PRINTFLIKE(3,4);
 void sieve_debug_internal (mu_sieve_printf_t printer, void *data,
-			   const char *fmt, ...);
+			   const char *fmt, ...) MU_PRINTFLIKE(3,4);
 void sieve_print_value (mu_sieve_value_t *val, mu_sieve_printf_t printer,
 		        void *data);
 void sieve_print_value_list (mu_list_t list, mu_sieve_printf_t printer, void *data);

@@ -112,7 +112,7 @@ extern int check_quota (struct mu_auth_data *auth,
 
 int mda (mu_mailbox_t mbx, char *username);
 int switch_user_id (struct mu_auth_data *auth, int user);
-void mailer_err (char *fmt, ...);
+void mailer_err (char *fmt, ...) MU_PRINTFLIKE(1,2);
 
 #ifdef WITH_GUILE
 struct mda_data

@@ -302,7 +302,7 @@ extern int msgset_member (msgset_t *set, size_t n);
 extern msgset_t *msgset_negate (msgset_t *set);
 extern size_t msgset_count (msgset_t *set);
 
-extern int util_do_command (const char *cmd, ...);
+extern int util_do_command (const char *cmd, ...) MU_PRINTFLIKE(1,2);
 
 extern int util_foreach_msg (int argc, char **argv, int flags,
 			     msg_handler_t func, void *data);
@@ -353,7 +353,7 @@ extern void util_strupper (char *str);
 extern void util_escape_percent (char **str);
 extern char *util_outfolder_name (char *str);
 extern void util_save_outgoing (mu_message_t msg, char *savefile);
-extern void util_error (const char *format, ...);
+extern void util_error (const char *format, ...) MU_PRINTFLIKE(1,2);
 extern int util_error_range (size_t msgno);
 extern void util_noapp (void);
 extern int util_tempfile (char **namep);
@@ -365,7 +365,7 @@ extern int util_get_hdr_value (mu_header_t hdr, const char *name, char **value);
 extern int util_merge_addresses (char **addr_str, const char *value);
 extern int util_header_expand (mu_header_t *hdr);
 extern int util_get_message (mu_mailbox_t mbox, size_t msgno, mu_message_t *msg);
-void util_cache_command (mu_list_t *list, const char *fmt, ...);
+void util_cache_command (mu_list_t *list, const char *fmt, ...) MU_PRINTFLIKE(2,3);
 void util_run_cached_commands (mu_list_t *list);
 const char *util_reply_prefix (void);
 void util_rfc2047_decode (char **value);

@@ -259,8 +259,8 @@ int mh_global_sequences_iterate (mh_context_iterator fp, void *data);
 void mh_global_sequences_drop (void);
 
 int mh_interactive_mode_p (void);
-int mh_getyn (const char *fmt, ...);
-int mh_getyn_interactive (const char *fmt, ...);
+int mh_getyn (const char *fmt, ...) MU_PRINTFLIKE(1,2);
+int mh_getyn_interactive (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 int mh_check_folder (const char *pathname, int confirm);
 int mh_makedir (const char *p);
 
@@ -273,7 +273,7 @@ void mh_format_debug (int val);
 void mh_format_free (mh_format_t *fmt);
 mh_builtin_t *mh_lookup_builtin (char *name, int *rest);
 
-void mh_error (const char *fmt, ...);
+void mh_error (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 void mh_err_memory (int fatal);
 
 FILE *mh_audit_open (char *name, mu_mailbox_t mbox);
@@ -364,6 +364,6 @@ void mh_comp_draft (const char *formfile, const char *defformfile,
 		    const char *draftfile);
 int check_draft_disposition (struct mh_whatnow_env *wh, int use_draft);
 
-void ali_parse_error (char *fmt, ...);
+void ali_parse_error (char *fmt, ...) MU_PRINTFLIKE(1,2); 
 void ali_verbatim (int enable);
 

@@ -249,7 +249,7 @@ extern int pop3d_touchlock      (void);
 extern int pop3d_uidl           (const char *);
 extern int pop3d_user           (const char *);
 extern int pop3d_unlock         (void);
-extern void pop3d_outf          (const char *fmt, ...);
+extern void pop3d_outf          (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 
 extern void pop3d_setio         (FILE *in, FILE *out);
 extern char *pop3d_readline     (char *, size_t);