diff --git a/src/buffer.c b/src/buffer.c
index 668cd9c..294bc9b 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2476,9 +2476,9 @@
 	{
 	    IObuff[len++] = ' ';
 	} while (--i > 0 && len < IOSIZE - 18);
-	sprintf((char *)IObuff + len, _("line %ld"),
-		buf == curbuf ? curwin->w_cursor.lnum :
-				(long)buflist_findlnum(buf));
+	vim_snprintf((char *)IObuff + len, IOSIZE - len, _("line %ld"),
+		buf == curbuf ? curwin->w_cursor.lnum
+					       : (long)buflist_findlnum(buf));
 	msg_outtrans(IObuff);
 	out_flush();	    /* output one line at a time */
 	ui_breakcheck();
@@ -2852,6 +2852,7 @@
     int		n;
     char_u	*p;
     char_u	*buffer;
+    size_t	len;
 
     buffer = alloc(IOSIZE);
     if (buffer == NULL)
@@ -2878,7 +2879,8 @@
 					  (int)(IOSIZE - (p - buffer)), TRUE);
     }
 
-    sprintf((char *)buffer + STRLEN(buffer),
+    len = STRLEN(buffer);
+    vim_snprintf((char *)buffer + len, IOSIZE - len,
 	    "\"%s%s%s%s%s%s",
 	    curbufIsChanged() ? (shortmess(SHM_MOD)
 					  ?  " [+]" : _(" [Modified]")) : " ",
@@ -2906,24 +2908,27 @@
     else
 	n = (int)(((long)curwin->w_cursor.lnum * 100L) /
 					    (long)curbuf->b_ml.ml_line_count);
+    len = STRLEN(buffer);
     if (curbuf->b_ml.ml_flags & ML_EMPTY)
     {
-	STRCPY(buffer + STRLEN(buffer), _(no_lines_msg));
+	vim_snprintf((char *)buffer + len, IOSIZE - len, "%s", _(no_lines_msg));
     }
 #ifdef FEAT_CMDL_INFO
     else if (p_ru)
     {
 	/* Current line and column are already on the screen -- webb */
 	if (curbuf->b_ml.ml_line_count == 1)
-	    sprintf((char *)buffer + STRLEN(buffer), _("1 line --%d%%--"), n);
+	    vim_snprintf((char *)buffer + len, IOSIZE - len,
+		    _("1 line --%d%%--"), n);
 	else
-	    sprintf((char *)buffer + STRLEN(buffer), _("%ld lines --%d%%--"),
+	    vim_snprintf((char *)buffer + len, IOSIZE - len,
+		    _("%ld lines --%d%%--"),
 					 (long)curbuf->b_ml.ml_line_count, n);
     }
 #endif
     else
     {
-	sprintf((char *)buffer + STRLEN(buffer),
+	vim_snprintf((char *)buffer + len, IOSIZE - len,
 		_("line %ld of %ld --%d%%-- col "),
 		(long)curwin->w_cursor.lnum,
 		(long)curbuf->b_ml.ml_line_count,
@@ -3630,7 +3635,8 @@
 	    if (*wp->w_buffer->b_p_ft != NUL
 		    && STRLEN(wp->w_buffer->b_p_ft) < TMPLEN - 3)
 	    {
-		sprintf((char *)tmp, "[%s]", wp->w_buffer->b_p_ft);
+		vim_snprintf((char *)tmp, sizeof(tmp), "[%s]",
+							wp->w_buffer->b_p_ft);
 		str = tmp;
 	    }
 	    break;
@@ -3640,7 +3646,8 @@
 	    if (*wp->w_buffer->b_p_ft != NUL
 		    && STRLEN(wp->w_buffer->b_p_ft) < TMPLEN - 2)
 	    {
-		sprintf((char *)tmp, ",%s", wp->w_buffer->b_p_ft);
+		vim_snprintf((char *)tmp, sizeof(tmp), ",%s",
+							wp->w_buffer->b_p_ft);
 		for (t = tmp; *t != 0; t++)
 		    *t = TOUPPER_LOC(*t);
 		str = tmp;
@@ -3768,10 +3775,12 @@
 		*t++ = '%';
 		*t = t[-3];
 		*++t = 0;
-		sprintf((char *)p, (char *)nstr, 0, num, n);
+		vim_snprintf((char *)p, outlen - (p - out), (char *)nstr,
+								   0, num, n);
 	    }
 	    else
-		sprintf((char *)p, (char *)nstr, minwid, num);
+		vim_snprintf((char *)p, outlen - (p - out), (char *)nstr,
+								 minwid, num);
 	    p += STRLEN(p);
 	}
 	else
@@ -3917,8 +3926,8 @@
 
 #if defined(FEAT_STL_OPT) || defined(FEAT_CMDL_INFO) || defined(PROTO)
 /*
- * Get relative cursor position in window, in the form 99%, using "Top", "Bot"
- * or "All" when appropriate.
+ * Get relative cursor position in window into "str[]", in the form 99%, using
+ * "Top", "Bot" or "All" when appropriate.
  */
     void
 get_rel_pos(wp, str)
@@ -4694,7 +4703,7 @@
     max_buffers = get_viminfo_parameter('%');
 
     /* Allocate room for the file name, lnum and col. */
-    line = alloc(MAXPATHL + 30);
+    line = alloc(MAXPATHL + 40);
     if (line == NULL)
 	return;
 
@@ -5076,22 +5085,13 @@
     {
 	if (buf->b_signlist != NULL)
 	{
-#ifdef HAVE_SNPRINTF
-	    snprintf
-#else
-	    sprintf
-#endif
-		(lbuf,
-#ifdef HAVE_SNPRINTF
-		 BUFSIZ,
-#endif
-		    _("Signs for %s:"), buf->b_fname);
+	    vim_snprintf(lbuf, BUFSIZ, _("Signs for %s:"), buf->b_fname);
 	    MSG_PUTS_ATTR(lbuf, hl_attr(HLF_D));
 	    msg_putchar('\n');
 	}
 	for (p = buf->b_signlist; p != NULL; p = p->next)
 	{
-	    sprintf(lbuf, _("    line=%ld  id=%d  name=%s"),
+	    vim_snprintf(lbuf, BUFSIZ, _("    line=%ld  id=%d  name=%s"),
 			   (long)p->lnum, p->id, sign_typenr2name(p->typenr));
 	    MSG_PUTS(lbuf);
 	    msg_putchar('\n');
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 38a7d44..9d9062a 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -1054,21 +1054,11 @@
 
 	if (p_verbose >= 15 && sourcing_name != NULL)
 	{
-	    int	c = -1;
-
 	    ++no_wait_return;
 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
-	    /* Truncate long lines, smsg() can't handle that. */
-	    if (STRLEN(cmdline_copy) > 200)
-	    {
-		c = cmdline_copy[200];
-		cmdline_copy[200] = NUL;
-	    }
 	    smsg((char_u *)_("line %ld: %s"),
 					   (long)sourcing_lnum, cmdline_copy);
 	    msg_puts((char_u *)"\n");   /* don't overwrite this either */
-	    if (c >= 0)
-		cmdline_copy[200] = c;
 	    cmdline_row = msg_row;
 	    --no_wait_return;
 	}
@@ -1341,7 +1331,8 @@
 	    switch (current_exception->type)
 	    {
 		case ET_USER:
-		    sprintf((char *)IObuff, _("E605: Exception not caught: %s"),
+		    vim_snprintf((char *)IObuff, IOSIZE,
+			    _("E605: Exception not caught: %s"),
 			    current_exception->value);
 		    p = vim_strsave(IObuff);
 		    break;
@@ -4802,7 +4793,7 @@
 		if (n == 1)
 		    STRCPY(buff, _("1 more file to edit.  Quit anyway?"));
 		else
-		    sprintf((char *)buff,
+		    vim_snprintf((char *)buff, IOSIZE,
 			      _("%d more files to edit.  Quit anyway?"), n);
 		if (vim_dialog_yesno(VIM_QUESTION, NULL, buff, 1) == VIM_YES)
 		    return OK;
@@ -9902,6 +9893,10 @@
 #endif
 
 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG) || defined(PROTO)
+/*
+ * Make a dialog message in "buff[IOSIZE]".
+ * "format" must contain "%.*s".
+ */
     void
 dialog_msg(buff, format, fname)
     char_u	*buff;
diff --git a/src/if_ruby.c b/src/if_ruby.c
index 9ef504c..112b91e 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -474,7 +474,7 @@
 	    char *p;
 
 	    epath = rb_class_path(eclass);
-	    snprintf(buff, BUFSIZ, "%s: %s",
+	    vim_snprintf(buff, BUFSIZ, "%s: %s",
 		     RSTRING(epath)->ptr, RSTRING(einfo)->ptr);
 	    p = strchr(buff, '\n');
 	    if (p) *p = '\0';
@@ -482,7 +482,7 @@
 	}
 	break;
     default:
-	snprintf(buff, BUFSIZ, _("E273: unknown longjmp status %d"), state);
+	vim_snprintf(buff, BUFSIZ, _("E273: unknown longjmp status %d"), state);
 	EMSG(buff);
 	break;
     }
diff --git a/src/if_sniff.c b/src/if_sniff.c
index 4cb0bee..7730e5b 100644
--- a/src/if_sniff.c
+++ b/src/if_sniff.c
@@ -817,14 +817,15 @@
 		vi_open_file(file);
 	    else if (buf!=curbuf)
 	    {
-		sprintf(VICommand, SelectBuf, file);
+		vim_snprintf(VICommand, sizeof(VICommand), SelectBuf, file);
 		vi_exec_cmd(VICommand);
 	    }
 	    if (command == 'o')
 		vi_set_cursor_pos((long)position);
 	    else
 	    {
-		sprintf(VICommand, GotoLine, (int)position);
+		vim_snprintf(VICommand, sizeof(VICommand), GotoLine,
+							       (int)position);
 		vi_exec_cmd(VICommand);
 	    }
 	    checkpcmark();	/* [mark.c] */
@@ -853,7 +854,7 @@
 	    buf = vi_find_buffer(file);
 	    if (buf && !buf->b_changed) /* delete buffer only if not modified */
 	    {
-		sprintf(VICommand, DeleteBuf, file);
+		vim_snprintf(VICommand, sizeof(VICommand), DeleteBuf, file);
 		vi_exec_cmd(VICommand);
 	    }
 	    vi_open_file(new_path);
@@ -875,7 +876,8 @@
 		    buf->b_flags |= BF_CHECK_RO + BF_NEVERLOADED;
 		    if (writable && !buf->b_changed)
 		    {
-			sprintf(VICommand, UnloadBuf, file);
+			vim_snprintf(VICommand, sizeof(VICommand), UnloadBuf,
+									file);
 			vi_exec_cmd(VICommand);
 		    }
 		}
@@ -895,7 +897,7 @@
 
 	    if (tab_width > 0 && tab_width <= 16)
 	    {
-		sprintf(VICommand, SetTab, tab_width);
+		vim_snprintf(VICommand, sizeof(VICommand), SetTab, tab_width);
 		vi_exec_cmd(VICommand);
 	    }
 	    break;
@@ -1030,7 +1032,7 @@
 	}
 
 	if (symbol)
-	    sprintf(cmdstr, "%c%s%s%ld%s%s\n",
+	    vim_snprintf(cmdstr, sizeof(cmdstr), "%c%s%s%ld%s%s\n",
 		command->cmd_code,
 		buffer_name,
 		sniff_rq_sep,
@@ -1039,7 +1041,8 @@
 		symbol
 	    );
 	else
-	    sprintf(cmdstr, "%c%s\n", command->cmd_code, buffer_name);
+	    vim_snprintf(cmdstr, sizeof(cmdstr), "%c%s\n",
+		    command->cmd_code, buffer_name);
     }
     else    /* simple request */
     {
@@ -1051,7 +1054,8 @@
     {
 	if ((cmd_type & NEED_SYMBOL) && !(cmd_type & EMPTY_SYMBOL))
 	{
-	    sprintf(msgtxt, "%s: %s", _(command->cmd_msg), symbol);
+	    vim_snprintf(msgtxt, sizeof(msgtxt), "%s: %s",
+						 _(command->cmd_msg), symbol);
 	    vi_msg(msgtxt);
 	}
 	else
diff --git a/src/integration.c b/src/integration.c
index 05a9dec..48cac53 100644
--- a/src/integration.c
+++ b/src/integration.c
@@ -182,7 +182,8 @@
 			char buf[20];
 
 			ackNum = atoi(&cmd[4]);
-			sprintf(buf, NOCATGETS("ack %d\n"), ackNum);
+			vim_snprintf(buf, sizeof(buf),
+					       NOCATGETS("ack %d\n"), ackNum);
 			write(sd, buf, strlen(buf));
 		} else if (strncmp(cmd,
 		    NOCATGETS("addMarkType "), 12) == 0) {
@@ -277,7 +278,8 @@
 			file  = strtok(&cmd[12], " ");
 			markid = atoi(strtok(NULL, " "));
 			line = workshop_get_mark_lineno(file, markid);
-			sprintf(buf, NOCATGETS("markLine %s %d %d\n"),
+			vim_snprintf(buf, sizeof(buf),
+					     NOCATGETS("markLine %s %d %d\n"),
 			    file, markid, line);
 			write(sd, buf, strlen(buf));
 		} else if (cmd[1] == 'o' && cmd[4] == 'L' &&
@@ -302,29 +304,34 @@
 		} else if (strcmp(cmd, NOCATGETS("getCurrentFile")) == 0) {
 			char *f = workshop_test_getcurrentfile();
 			char buffer[2*MAXPATHLEN];
-			sprintf(buffer, NOCATGETS("currentFile %d %s"),
+			vim_snprintf(buffer, sizeof(buffer),
+					NOCATGETS("currentFile %d %s"),
 				f ? strlen(f) : 0, f ? f : "");
 			workshop_send_message(buffer);
 		} else if (strcmp(cmd, NOCATGETS("getCursorRow")) == 0) {
 			int row = workshop_test_getcursorrow();
 			char buffer[2*MAXPATHLEN];
-			sprintf(buffer, NOCATGETS("cursorRow %d"), row);
+			vim_snprintf(buffer, sizeof(buffer),
+					NOCATGETS("cursorRow %d"), row);
 			workshop_send_message(buffer);
 		} else if (strcmp(cmd, NOCATGETS("getCursorCol")) == 0) {
 			int col = workshop_test_getcursorcol();
 			char buffer[2*MAXPATHLEN];
-			sprintf(buffer, NOCATGETS("cursorCol %d"), col);
+			vim_snprintf(buffer, sizeof(buffer),
+					NOCATGETS("cursorCol %d"), col);
 			workshop_send_message(buffer);
 		} else if (strcmp(cmd, NOCATGETS("getCursorRowText")) == 0) {
 			char *t = workshop_test_getcursorrowtext();
 			char buffer[2*MAXPATHLEN];
-			sprintf(buffer, NOCATGETS("cursorRowText %d %s"),
+			vim_snprintf(buffer, sizeof(buffer),
+					NOCATGETS("cursorRowText %d %s"),
 				t ? strlen(t) : 0, t ? t : "");
 			workshop_send_message(buffer);
 		} else if (strcmp(cmd, NOCATGETS("getSelectedText")) == 0) {
 			char *t = workshop_test_getselectedtext();
 			char buffer[2*MAXPATHLEN];
-			sprintf(buffer, NOCATGETS("selectedText %d %s"),
+			vim_snprintf(buffer, sizeof(buffer),
+					NOCATGETS("selectedText %d %s"),
 				t ? strlen(t) : 0, t ? t : "");
 			workshop_send_message(buffer);
 #endif
@@ -709,7 +716,7 @@
 		char buf[BUFSIZ];
 
 		unlink(file);
-		sprintf(buf, "date > %s", file);
+		vim_snprintf(buf, sizeof(buf), "date > %s", file);
 		system(buf);
 		dfd = fopen(file, "a");
 	} else {
@@ -717,13 +724,13 @@
 	}
 #endif
 
-	sprintf(buf, NOCATGETS("connected %s %s %s\n"),
+	vim_snprintf(buf, sizeof(buf), NOCATGETS("connected %s %s %s\n"),
 		workshop_get_editor_name(),
 		PROTOCOL_VERSION,
 		workshop_get_editor_version());
 	write(sd, buf, strlen(buf));
 
-	sprintf(buf, NOCATGETS("ack 1\n"));
+	vim_snprintf(buf, sizeof(buf), NOCATGETS("ack 1\n"));
 	write(sd, buf, strlen(buf));
 }
 
@@ -1047,21 +1054,24 @@
 void workshop_file_closed(char *filename)
 {
 	char buffer[2*MAXPATHLEN];
-	sprintf(buffer, NOCATGETS("deletedFile %s\n"), filename);
+	vim_snprintf(buffer, sizeof(buffer),
+			NOCATGETS("deletedFile %s\n"), filename);
 	write(sd, buffer, strlen(buffer));
 }
 
 void workshop_file_closed_lineno(char *filename, int lineno)
 {
 	char buffer[2*MAXPATHLEN];
-	sprintf(buffer, NOCATGETS("deletedFile %s %d\n"), filename, lineno);
+	vim_snprintf(buffer, sizeof(buffer),
+			NOCATGETS("deletedFile %s %d\n"), filename, lineno);
 	write(sd, buffer, strlen(buffer));
 }
 
 void workshop_file_opened(char *filename, int readOnly)
 {
 	char buffer[2*MAXPATHLEN];
-	sprintf(buffer, NOCATGETS("loadedFile %s %d\n"), filename, readOnly);
+	vim_snprintf(buffer, sizeof(buffer),
+			NOCATGETS("loadedFile %s %d\n"), filename, readOnly);
 	write(sd, buffer, strlen(buffer));
 }
 
@@ -1069,7 +1079,8 @@
 void workshop_file_saved(char *filename)
 {
 	char buffer[2*MAXPATHLEN];
-	sprintf(buffer, NOCATGETS("savedFile %s\n"), filename);
+	vim_snprintf(buffer, sizeof(buffer),
+			NOCATGETS("savedFile %s\n"), filename);
 	write(sd, buffer, strlen(buffer));
 
 	/* Let editor report any moved marks that the eserve client
@@ -1080,14 +1091,16 @@
 void workshop_move_mark(char *filename, int markId, int newLineno)
 {
 	char buffer[2*MAXPATHLEN];
-	sprintf(buffer, NOCATGETS("moveMark %s %d %d\n"), filename, markId, newLineno);
+	vim_snprintf(buffer, sizeof(buffer),
+			NOCATGETS("moveMark %s %d %d\n"), filename, markId, newLineno);
 	write(sd, buffer, strlen(buffer));
 }
 
 void workshop_file_modified(char *filename)
 {
 	char buffer[2*MAXPATHLEN];
-	sprintf(buffer, NOCATGETS("modifiedFile %s\n"), filename);
+	vim_snprintf(buffer, sizeof(buffer),
+			NOCATGETS("modifiedFile %s\n"), filename);
 	write(sd, buffer, strlen(buffer));
 }
 
@@ -1097,7 +1110,8 @@
 
 	if (sd >= 0)
 	{
-		sprintf(buffer, NOCATGETS("frameAt %d %d %d %d\n"),
+		vim_snprintf(buffer, sizeof(buffer),
+				NOCATGETS("frameAt %d %d %d %d\n"),
 				new_x, new_y, new_w, new_h);
 		write(sd, buffer, strlen(buffer));
 	}
@@ -1150,7 +1164,8 @@
 			}
 		}
 
-		sprintf(buf, NOCATGETS("toolVerb %s %s %d,%d %d,%d %d,%d %d %s\n"),
+		vim_snprintf(buf, sizeof(buf),
+			NOCATGETS("toolVerb %s %s %d,%d %d,%d %d,%d %d %s\n"),
 			verb,
 			filename,
 			curLine, curCol,
diff --git a/src/message.c b/src/message.c
index 8b4a2b3..7efe28c 100644
--- a/src/message.c
+++ b/src/message.c
@@ -313,6 +313,15 @@
 smsg_attr __ARGS((int, char_u *, long, long, long,
 			long, long, long, long, long, long, long));
 
+int vim_snprintf __ARGS((char *, size_t, char *, long, long, long,
+				   long, long, long, long, long, long, long));
+
+/*
+ * smsg(str, arg, ...) is like using sprintf(buf, str, arg, ...) and then
+ * calling msg(buf).
+ * The buffer used is IObuff, the message is truncated at IOSIZE.
+ */
+
 /* VARARGS */
     int
 #ifdef __BORLANDC__
@@ -335,12 +344,16 @@
     char_u	*s;
     long	a1, a2, a3, a4, a5, a6, a7, a8, a9, a10;
 {
-    sprintf((char *)IObuff, (char *)s, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10);
+    vim_snprintf((char *)IObuff, IOSIZE, (char *)s,
+				     a1, a2, a3, a4, a5, a6, a7, a8, a9, a10);
     return msg_attr(IObuff, attr);
 }
 
 # else /* HAVE_STDARG_H */
 
+int vim_snprintf(char *str, size_t str_m, char *fmt, ...);
+static int vim_vsnprintf(char *str, size_t str_m, char *fmt, va_list ap);
+
     int
 #ifdef __BORLANDC__
 _RTLENTRYF
@@ -350,11 +363,7 @@
     va_list arglist;
 
     va_start(arglist, s);
-# ifdef HAVE_VSNPRINTF
-    vsnprintf((char *)IObuff, IOSIZE, (char *)s, arglist);
-# else
-    vsprintf((char *)IObuff, (char *)s, arglist);
-# endif
+    vim_vsnprintf((char *)IObuff, IOSIZE, (char *)s, arglist);
     va_end(arglist);
     return msg(IObuff);
 }
@@ -368,11 +377,7 @@
     va_list arglist;
 
     va_start(arglist, s);
-# ifdef HAVE_VSNPRINTF
-    vsnprintf((char *)IObuff, IOSIZE, (char *)s, arglist);
-# else
-    vsprintf((char *)IObuff, (char *)s, arglist);
-# endif
+    vim_vsnprintf((char *)IObuff, IOSIZE, (char *)s, arglist);
     va_end(arglist);
     return msg_attr(IObuff, attr);
 }
@@ -645,18 +650,7 @@
 #endif
 	    )
 	return TRUE;		/* no error messages at the moment */
-
-    /* Check for NULL strings (just in case) */
-    if (a1 == NULL)
-	a1 = (char_u *)"[NULL]";
-    if (a2 == NULL)
-	a2 = (char_u *)"[NULL]";
-
-    /* Check for very long strings (can happen with ":help ^A<CR>"). */
-    if (STRLEN(s) + STRLEN(a1) + STRLEN(a2) >= (size_t)IOSIZE)
-	a1 = a2 = (char_u *)_("[string too long]");
-
-    sprintf((char *)IObuff, (char *)s, (char *)a1, (char *)a2);
+    vim_snprintf((char *)IObuff, IOSIZE, (char *)s, (char *)a1, (char *)a2);
     return emsg(IObuff);
 }
 
@@ -674,7 +668,7 @@
 #endif
 	    )
 	return TRUE;		/* no error messages at the moment */
-    sprintf((char *)IObuff, (char *)s, n);
+    vim_snprintf((char *)IObuff, IOSIZE, (char *)s, n);
     return emsg(IObuff);
 }
 
@@ -3205,3 +3199,699 @@
     return fname;
 }
 #endif
+
+/*
+ * This code was included to provide a portable vsnprintf() and snprintf().
+ * Some systems may provide their own, but we always use these for
+ * consistency.
+ *
+ * This code is based on snprintf.c - a portable implementation of snprintf
+ * by Mark Martinec <mark.martinec@ijs.si>, Version 2.2, 2000-10-06.
+ * It was heavely modified to fit in Vim.
+ * The original code, including useful comments, can be found here:
+ *	http://www.ijs.si/software/snprintf/
+ *
+ * This snprintf() only supports the following conversion specifiers:
+ * s, c, d, u, o, x, X, p  (and synonyms: i, D, U, O - see below)
+ * with flags: '-', '+', ' ', '0' and '#'.
+ * An asterisk is supported for field width as well as precision.
+ *
+ * Length modifiers 'h' (short int) and 'l' (long int) are supported.
+ * 'll' (long long int) is not supported.
+ *
+ * It is permitted for str_m to be zero, and it is permitted to specify NULL
+ * pointer for resulting string argument if str_m is zero (as per ISO C99).
+ *
+ * The return value is the number of characters which would be generated
+ * for the given input, excluding the trailing null. If this value
+ * is greater or equal to str_m, not all characters from the result
+ * have been stored in str, output bytes beyond the (str_m-1) -th character
+ * are discarded. If str_m is greater than zero it is guaranteed
+ * the resulting string will be null-terminated.
+ */
+
+/*
+ * When va_list is not supported we only define vim_snprintf().
+ */
+
+/* When generating prototypes all of this is skipped, cproto doesn't
+ * understand this. */
+#ifndef PROTO
+# ifdef HAVE_STDARG_H
+    int
+vim_snprintf(char *str, size_t str_m, char *fmt, ...)
+{
+    va_list	ap;
+    int		str_l;
+
+    va_start(ap, fmt);
+    str_l = vim_vsnprintf(str, str_m, fmt, ap);
+    va_end(ap);
+    return str_l;
+}
+
+    static int
+vim_vsnprintf(str, str_m, fmt, ap)
+# else
+    /* clumsy way to work around missing va_list */
+#  define get_a_arg(i) (i == 1 ? a1 : i == 2 ? a2 : i == 3 ? a3 : i == 4 ? a4 : i == 5 ? a5 : i == 6 ? a6 : i == 7 ? a7 : i == 8 ? a8 : i == 9 ? a9 : a10)
+
+/* VARARGS */
+    int
+#ifdef __BORLANDC__
+_RTLENTRYF
+#endif
+vim_snprintf(str, str_m, fmt, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10)
+# endif
+    char	*str;
+    size_t	str_m;
+    char	*fmt;
+# ifdef HAVE_STDARG_H
+    va_list	ap;
+# else
+    long	a1, a2, a3, a4, a5, a6, a7, a8, a9, a10;
+# endif
+{
+    size_t	str_l = 0;
+    char	*p = fmt;
+# ifndef HAVE_STDARG_H
+    int		arg_idx = 1;
+# endif
+
+    if (p == NULL)
+	p = "";
+    while (*p != NUL)
+    {
+	if (*p != '%')
+	{
+	    char    *q = strchr(p + 1, '%');
+	    size_t  n = (q == NULL) ? STRLEN(p) : (q - p);
+
+	    if (str_l < str_m)
+	    {
+		size_t avail = str_m - str_l;
+
+		mch_memmove(str + str_l, p, n > avail ? avail : n);
+	    }
+	    p += n;
+	    str_l += n;
+	}
+	else
+	{
+	    size_t  min_field_width = 0, precision = 0;
+	    int	    zero_padding = 0, precision_specified = 0, justify_left = 0;
+	    int	    alternate_form = 0, force_sign = 0;
+
+	    /* If both the ' ' and '+' flags appear, the ' ' flag should be
+	     * ignored. */
+	    int	    space_for_positive = 1;
+
+	    /* allowed values: \0, h, l, L */
+	    char    length_modifier = '\0';
+
+	    /* temporary buffer for simple numeric->string conversion */
+	    char    tmp[32];
+
+	    /* string address in case of string argument */
+	    char    *str_arg;
+
+	    /* natural field width of arg without padding and sign */
+	    size_t  str_arg_l;
+
+	    /* unsigned char argument value - only defined for c conversion.
+	     * N.B. standard explicitly states the char argument for the c
+	     * conversion is unsigned */
+	    unsigned char uchar_arg;
+
+	    /* number of zeros to be inserted for numeric conversions as
+	     * required by the precision or minimal field width */
+	    size_t  number_of_zeros_to_pad = 0;
+
+	    /* index into tmp where zero padding is to be inserted */
+	    size_t  zero_padding_insertion_ind = 0;
+
+	    /* current conversion specifier character */
+	    char    fmt_spec = '\0';
+
+	    str_arg = NULL;
+	    p++;  /* skip '%' */
+
+	    /* parse flags */
+	    while (*p == '0' || *p == '-' || *p == '+' || *p == ' '
+						   || *p == '#' || *p == '\'')
+	    {
+		switch (*p)
+		{
+		    case '0': zero_padding = 1; break;
+		    case '-': justify_left = 1; break;
+		    case '+': force_sign = 1; space_for_positive = 0; break;
+		    case ' ': force_sign = 1;
+			      /* If both the ' ' and '+' flags appear, the ' '
+			       * flag should be ignored */
+			      break;
+		    case '#': alternate_form = 1; break;
+		    case '\'': break;
+		}
+		p++;
+	    }
+	    /* If the '0' and '-' flags both appear, the '0' flag should be
+	     * ignored. */
+
+	    /* parse field width */
+	    if (*p == '*')
+	    {
+		int j;
+
+		p++;
+#ifndef HAVE_STDARG_H
+		j = get_a_arg(arg_idx);
+		++arg_idx;
+#else
+		j = va_arg(ap, int);
+#endif
+		if (j >= 0)
+		    min_field_width = j;
+		else
+		{
+		    min_field_width = -j;
+		    justify_left = 1;
+		}
+	    }
+	    else if (VIM_ISDIGIT((int)(*p)))
+	    {
+		/* size_t could be wider than unsigned int; make sure we treat
+		 * argument like common implementations do */
+		unsigned int uj = *p++ - '0';
+
+		while (VIM_ISDIGIT((int)(*p)))
+		    uj = 10 * uj + (unsigned int)(*p++ - '0');
+		min_field_width = uj;
+	    }
+
+	    /* parse precision */
+	    if (*p == '.')
+	    {
+		p++;
+		precision_specified = 1;
+		if (*p == '*')
+		{
+		    int j;
+
+#ifndef HAVE_STDARG_H
+		    j = get_a_arg(arg_idx);
+		    ++arg_idx;
+#else
+		    j = va_arg(ap, int);
+#endif
+		    p++;
+		    if (j >= 0)
+			precision = j;
+		    else
+		    {
+			precision_specified = 0;
+			precision = 0;
+		    }
+		}
+		else if (VIM_ISDIGIT((int)(*p)))
+		{
+		    /* size_t could be wider than unsigned int; make sure we
+		     * treat argument like common implementations do */
+		    unsigned int uj = *p++ - '0';
+
+		    while (VIM_ISDIGIT((int)(*p)))
+			uj = 10 * uj + (unsigned int)(*p++ - '0');
+		    precision = uj;
+		}
+	    }
+
+	    /* parse 'h', 'l' and 'll' length modifiers */
+	    if (*p == 'h' || *p == 'l')
+	    {
+		length_modifier = *p;
+		p++;
+		if (length_modifier == 'l' && *p == 'l')
+		{
+		    /* double l = long long */
+		    length_modifier = 'l';	/* treat it as a single 'l' */
+		    p++;
+		}
+	    }
+	    fmt_spec = *p;
+
+	    /* common synonyms: */
+	    switch (fmt_spec)
+	    {
+		case 'i': fmt_spec = 'd'; break;
+		case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
+		case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
+		case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
+		default: break;
+	    }
+
+	    /* get parameter value, do initial processing */
+	    switch (fmt_spec)
+	    {
+		/* '%' and 'c' behave similar to 's' regarding flags and field
+		 * widths */
+	    case '%':
+	    case 'c':
+	    case 's':
+		length_modifier = '\0';
+		zero_padding = 0;    /* turn zero padding off for string
+					conversions */
+		str_arg_l = 1;
+		switch (fmt_spec)
+		{
+		case '%':
+		    str_arg = p;
+		    break;
+
+		case 'c':
+		    {
+			int j;
+#ifndef HAVE_STDARG_H
+			j = get_a_arg(arg_idx);
+			++arg_idx;
+#else
+			j = va_arg(ap, int);
+#endif
+			/* standard demands unsigned char */
+			uchar_arg = (unsigned char)j;
+			str_arg = (char *)&uchar_arg;
+			break;
+		    }
+
+		case 's':
+#ifndef HAVE_STDARG_H
+		    str_arg = (char *)get_a_arg(arg_idx);
+		    ++arg_idx;
+#else
+		    str_arg = va_arg(ap, char *);
+#endif
+		    if (str_arg == NULL)
+		    {
+			str_arg = "[NULL]";
+			str_arg_l = 6;
+		    }
+		    /* make sure not to address string beyond the specified
+		     * precision !!! */
+		    else if (!precision_specified)
+			str_arg_l = strlen(str_arg);
+		    /* truncate string if necessary as requested by precision */
+		    else if (precision == 0)
+			str_arg_l = 0;
+		    else
+		    {
+			/* memchr on HP does not like n > 2^31  !!! */
+			char *q = memchr(str_arg, '\0',
+				precision <= 0x7fffffff ? precision
+								: 0x7fffffff);
+			str_arg_l = (q == NULL) ? precision : q - str_arg;
+		    }
+		    break;
+
+		default:
+		    break;
+		}
+		break;
+
+	    case 'd': case 'u': case 'o': case 'x': case 'X': case 'p':
+		{
+		    /* NOTE: the u, o, x, X and p conversion specifiers
+		     * imply the value is unsigned;  d implies a signed
+		     * value */
+
+		    /* 0 if numeric argument is zero (or if pointer is
+		     * NULL for 'p'), +1 if greater than zero (or nonzero
+		     * for unsigned arguments), -1 if negative (unsigned
+		     * argument is never negative) */
+		    int arg_sign = 0;
+
+		    /* only defined for length modifier h, or for no
+		     * length modifiers */
+		    int int_arg = 0;
+		    unsigned int uint_arg = 0;
+
+		    /* only defined for length modifier l */
+		    long int long_arg = 0;
+		    unsigned long int ulong_arg = 0;
+
+		    /* pointer argument value -only defined for p
+		     * conversion */
+		    void *ptr_arg = NULL;
+
+		    if (fmt_spec == 'p')
+		    {
+			length_modifier = '\0';
+#ifndef HAVE_STDARG_H
+			ptr_arg = (void *)get_a_arg(arg_idx);
+			++arg_idx;
+#else
+			ptr_arg = va_arg(ap, void *);
+#endif
+			if (ptr_arg != NULL)
+			    arg_sign = 1;
+		    }
+		    else if (fmt_spec == 'd')
+		    {
+			/* signed */
+			switch (length_modifier)
+			{
+			case '\0':
+			case 'h':
+			    /* It is non-portable to specify a second argument
+			     * of char or short to va_arg, because arguments
+			     * seen by the called function are not char or
+			     * short.  C converts char and short arguments to
+			     * int before passing them to a function.  */
+#ifndef HAVE_STDARG_H
+			    int_arg = get_a_arg(arg_idx);
+			    ++arg_idx;
+#else
+			    int_arg = va_arg(ap, int);
+#endif
+			    if (int_arg > 0)
+				arg_sign =  1;
+			    else if (int_arg < 0)
+				arg_sign = -1;
+			    break;
+			case 'l':
+#ifndef HAVE_STDARG_H
+			    long_arg = get_a_arg(arg_idx);
+			    ++arg_idx;
+#else
+			    long_arg = va_arg(ap, long int);
+#endif
+			    if (long_arg > 0)
+				arg_sign =  1;
+			    else if (long_arg < 0)
+				arg_sign = -1;
+			    break;
+			}
+		    }
+		    else
+		    {
+			/* unsigned */
+			switch (length_modifier)
+			{
+			    case '\0':
+			    case 'h':
+#ifndef HAVE_STDARG_H
+				uint_arg = get_a_arg(arg_idx);
+				++arg_idx;
+#else
+				uint_arg = va_arg(ap, unsigned int);
+#endif
+				if (uint_arg != 0)
+				    arg_sign = 1;
+				break;
+			    case 'l':
+#ifndef HAVE_STDARG_H
+				ulong_arg = get_a_arg(arg_idx);
+				++arg_idx;
+#else
+				ulong_arg = va_arg(ap, unsigned long int);
+#endif
+				if (ulong_arg != 0)
+				    arg_sign = 1;
+				break;
+			}
+		    }
+
+		    str_arg = tmp;
+		    str_arg_l = 0;
+
+		    /* NOTE:
+		     *   For d, i, u, o, x, and X conversions, if precision is
+		     *   specified, the '0' flag should be ignored. This is so
+		     *   with Solaris 2.6, Digital UNIX 4.0, HPUX 10, Linux,
+		     *   FreeBSD, NetBSD; but not with Perl.
+		     */
+		    if (precision_specified)
+			zero_padding = 0;
+		    if (fmt_spec == 'd')
+		    {
+			if (force_sign && arg_sign >= 0)
+			    tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+			/* leave negative numbers for sprintf to handle, to
+			 * avoid handling tricky cases like (short int)-32768 */
+		    }
+		    else if (alternate_form)
+		    {
+			if (arg_sign != 0
+				     && (fmt_spec == 'x' || fmt_spec == 'X') )
+			{
+			    tmp[str_arg_l++] = '0';
+			    tmp[str_arg_l++] = fmt_spec;
+			}
+			/* alternate form should have no effect for p
+			 * conversion, but ... */
+		    }
+
+		    zero_padding_insertion_ind = str_arg_l;
+		    if (!precision_specified)
+			precision = 1;   /* default precision is 1 */
+		    if (precision == 0 && arg_sign == 0)
+		    {
+			/* When zero value is formatted with an explicit
+			 * precision 0, the resulting formatted string is
+			 * empty (d, i, u, o, x, X, p).   */
+		    }
+		    else
+		    {
+			char	f[5];
+			int	f_l = 0;
+
+			/* construct a simple format string for sprintf */
+			f[f_l++] = '%';
+			if (!length_modifier)
+			    ;
+			else if (length_modifier == '2')
+			{
+			    f[f_l++] = 'l';
+			    f[f_l++] = 'l';
+			}
+			else
+			    f[f_l++] = length_modifier;
+			f[f_l++] = fmt_spec;
+			f[f_l++] = '\0';
+
+			if (fmt_spec == 'p')
+			    str_arg_l += sprintf(tmp + str_arg_l, f, ptr_arg);
+			else if (fmt_spec == 'd')
+			{
+			    /* signed */
+			    switch (length_modifier)
+			    {
+			    case '\0':
+			    case 'h': str_arg_l += sprintf(
+						 tmp + str_arg_l, f, int_arg);
+				      break;
+			    case 'l': str_arg_l += sprintf(
+						tmp + str_arg_l, f, long_arg);
+				      break;
+			    }
+			}
+			else
+			{
+			    /* unsigned */
+			    switch (length_modifier)
+			    {
+			    case '\0':
+			    case 'h': str_arg_l += sprintf(
+						tmp + str_arg_l, f, uint_arg);
+				      break;
+			    case 'l': str_arg_l += sprintf(
+					       tmp + str_arg_l, f, ulong_arg);
+				      break;
+			    }
+			}
+
+			/* include the optional minus sign and possible
+			 * "0x" in the region before the zero padding
+			 * insertion point */
+			if (zero_padding_insertion_ind < str_arg_l
+				&& tmp[zero_padding_insertion_ind] == '-')
+			    zero_padding_insertion_ind++;
+			if (zero_padding_insertion_ind + 1 < str_arg_l
+				&& tmp[zero_padding_insertion_ind]   == '0'
+				&& (tmp[zero_padding_insertion_ind + 1] == 'x'
+				 || tmp[zero_padding_insertion_ind + 1] == 'X'))
+			    zero_padding_insertion_ind += 2;
+		    }
+
+		    {
+			size_t num_of_digits = str_arg_l
+						 - zero_padding_insertion_ind;
+
+			if (alternate_form && fmt_spec == 'o'
+				/* unless zero is already the first
+				 * character */
+				&& !(zero_padding_insertion_ind < str_arg_l
+				    && tmp[zero_padding_insertion_ind] == '0'))
+			{
+			    /* assure leading zero for alternate-form
+			     * octal numbers */
+			    if (!precision_specified
+					     || precision < num_of_digits + 1)
+			    {
+				/* precision is increased to force the
+				 * first character to be zero, except if a
+				 * zero value is formatted with an
+				 * explicit precision of zero */
+				precision = num_of_digits + 1;
+				precision_specified = 1;
+			    }
+			}
+			/* zero padding to specified precision? */
+			if (num_of_digits < precision)
+			    number_of_zeros_to_pad = precision - num_of_digits;
+		    }
+		    /* zero padding to specified minimal field width? */
+		    if (!justify_left && zero_padding)
+		    {
+			int n = min_field_width - (str_arg_l
+						    + number_of_zeros_to_pad);
+			if (n > 0)
+			    number_of_zeros_to_pad += n;
+		    }
+		    break;
+		}
+
+	    default:
+		/* unrecognized conversion specifier, keep format string
+		 * as-is */
+		zero_padding = 0;  /* turn zero padding off for non-numeric
+				      convers. */
+		justify_left = 1;
+		min_field_width = 0;                /* reset flags */
+
+		/* discard the unrecognized conversion, just keep *
+		 * the unrecognized conversion character          */
+		str_arg = p;
+		str_arg_l = 0;
+		if (*p != NUL)
+		    str_arg_l++;  /* include invalid conversion specifier
+				     unchanged if not at end-of-string */
+		break;
+	    }
+
+	    if (*p != NUL)
+		p++;     /* step over the just processed conversion specifier */
+
+	    /* insert padding to the left as requested by min_field_width;
+	     * this does not include the zero padding in case of numerical
+	     * conversions*/
+	    if (!justify_left)
+	    {
+		/* left padding with blank or zero */
+		int n = min_field_width - (str_arg_l + number_of_zeros_to_pad);
+
+		if (n > 0)
+		{
+		    if (str_l < str_m)
+		    {
+			size_t avail = str_m - str_l;
+
+			vim_memset(str + str_l, zero_padding ? '0' : ' ',
+						       n > avail ? avail : n);
+		    }
+		    str_l += n;
+		}
+	    }
+
+	    /* zero padding as requested by the precision or by the minimal
+	     * field width for numeric conversions required? */
+	    if (number_of_zeros_to_pad <= 0)
+	    {
+		/* will not copy first part of numeric right now, *
+		 * force it to be copied later in its entirety    */
+		zero_padding_insertion_ind = 0;
+	    }
+	    else
+	    {
+		/* insert first part of numerics (sign or '0x') before zero
+		 * padding */
+		int n = zero_padding_insertion_ind;
+
+		if (n > 0)
+		{
+		    if (str_l < str_m)
+		    {
+			size_t avail = str_m - str_l;
+
+			mch_memmove(str + str_l, str_arg,
+						       n > avail ? avail : n);
+		    }
+		    str_l += n;
+		}
+
+		/* insert zero padding as requested by the precision or min
+		 * field width */
+		n = number_of_zeros_to_pad;
+		if (n > 0)
+		{
+		    if (str_l < str_m)
+		    {
+			size_t avail = str_m-str_l;
+
+			vim_memset(str + str_l, '0', n > avail ? avail : n);
+		    }
+		    str_l += n;
+		}
+	    }
+
+	    /* insert formatted string
+	     * (or as-is conversion specifier for unknown conversions) */
+	    {
+		int n = str_arg_l - zero_padding_insertion_ind;
+
+		if (n > 0)
+		{
+		    if (str_l < str_m)
+		    {
+			size_t avail = str_m - str_l;
+
+			mch_memmove(str + str_l,
+				str_arg + zero_padding_insertion_ind,
+				n > avail ? avail : n);
+		    }
+		    str_l += n;
+		}
+	    }
+
+	    /* insert right padding */
+	    if (justify_left)
+	    {
+		/* right blank padding to the field width */
+		int n = min_field_width - (str_arg_l + number_of_zeros_to_pad);
+
+		if (n > 0)
+		{
+		    if (str_l < str_m)
+		    {
+			size_t avail = str_m - str_l;
+
+			vim_memset(str + str_l, ' ', n > avail ? avail : n);
+		    }
+		    str_l += n;
+		}
+	    }
+	}
+    }
+
+    if (str_m > 0)
+    {
+	/* make sure the string is null-terminated even at the expense of
+	 * overwriting the last character (shouldn't happen, but just in case)
+	 * */
+	str[str_l <= str_m - 1 ? str_l : str_m - 1] = '\0';
+    }
+
+    /* Return the number of characters formatted (excluding trailing null
+     * character), that is, the number of characters that would have been
+     * written to the buffer if it were large enough. */
+    return (int)str_l;
+}
+
+#endif /* PROTO */
diff --git a/src/netbeans.c b/src/netbeans.c
index 19d1697..f6fb52c 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -403,7 +403,7 @@
 	}
     }
 
-    sprintf(buf, "AUTH %s\n", password);
+    vim_snprintf(buf, sizeof(buf), "AUTH %s\n", password);
     nb_send(buf, "netbeans_connect");
 
     sprintf(buf, "0:version=0 \"%s\"\n", ExtEdProtocolVersion);
@@ -2379,7 +2379,8 @@
 	}
 
 	strcpy(&keybuf[i], tok);
-	sprintf(cmdbuf, "<silent><%s> :nbkey %s<CR>", keybuf, keybuf);
+	vim_snprintf(cmdbuf, sizeof(cmdbuf),
+				"<silent><%s> :nbkey %s<CR>", keybuf, keybuf);
 	do_map(0, (char_u *)cmdbuf, NORMAL, FALSE);
 	tok = strtok(NULL, " ");
     }
@@ -2516,7 +2517,8 @@
 	    p = nb_quote(text);
 	    if (p != NULL)
 	    {
-		sprintf(buf, "0:balloonText=%d \"%s\"\n", cmdno, p);
+		vim_snprintf(buf, sizeof(buf),
+				       "0:balloonText=%d \"%s\"\n", cmdno, p);
 		vim_free(p);
 	    }
 	    nbdebug(("EVT: %s", buf));
@@ -2613,7 +2615,7 @@
     if (q == NULL || bp == NULL || bufp == NULL)
 	return;
 
-    sprintf(buffer, "%d:fileOpened=%d \"%s\" %s %s\n",
+    vim_snprintf(buffer, sizeof(buffer),  "%d:fileOpened=%d \"%s\" %s %s\n",
 	    bufno,
 	    bufno,
 	    (char *)q,
@@ -2649,7 +2651,7 @@
     else
 	bnum = 0;
 
-    sprintf(buffer, "%d:fileOpened=%d \"%s\" %s %s\n",
+    vim_snprintf(buffer, sizeof(buffer), "%d:fileOpened=%d \"%s\" %s %s\n",
 	    bnum,
 	    0,
 	    (char *)q,
@@ -2913,7 +2915,7 @@
 						 : nb_quote(curbuf->b_ffname);
 	if (q == NULL)
 	    return;
-	sprintf(buf, "0:fileOpened=%d \"%s\" %s %s\n", 0,
+	vim_snprintf(buf, sizeof(buf), "0:fileOpened=%d \"%s\" %s %s\n", 0,
 		q,
 		"T",  /* open in NetBeans */
 		"F"); /* modified */
@@ -2939,12 +2941,14 @@
      */
 
     /* now send keyCommand event */
-    sprintf(buf, "%d:keyCommand=%d \"%s\"\n", bufno, cmdno, keyName);
+    vim_snprintf(buf, sizeof(buf), "%d:keyCommand=%d \"%s\"\n",
+						       bufno, cmdno, keyName);
     nbdebug(("EVT: %s", buf));
     nb_send(buf, "netbeans_keycommand");
 
     /* New: do both at once and include the lnum/col. */
-    sprintf(buf, "%d:keyAtPos=%d \"%s\" %ld %ld/%ld\n", bufno, cmdno, keyName,
+    vim_snprintf(buf, sizeof(buf), "%d:keyAtPos=%d \"%s\" %ld %ld/%ld\n",
+	    bufno, cmdno, keyName,
 		off, (long)curwin->w_cursor.lnum, (long)curwin->w_cursor.col);
     nbdebug(("EVT: %s", buf));
     nb_send(buf, "netbeans_keycommand");
diff --git a/src/os_mac.c b/src/os_mac.c
index cc656f0..baab5a5 100644
--- a/src/os_mac.c
+++ b/src/os_mac.c
@@ -682,6 +682,7 @@
 	    && pw->pw_name != NULL && *(pw->pw_name) != NUL)
     {
 	STRNCPY(s, pw->pw_name, len);
+	s[len - 1] = NUL;
 	return OK;
     }
 #endif
diff --git a/src/proto.h b/src/proto.h
index cff55c3..e24ebb4 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -95,25 +95,32 @@
 # include "hashtable.pro"
 # include "main.pro"
 # include "mark.pro"
-# if !defined MESSAGE_FILE || defined(HAVE_STDARG_H)
-    /* These prototypes cannot be produced automatically and conflict with
-     * the old-style prototypes in message.c. */
-int
-#ifdef __BORLANDC__
-_RTLENTRYF
-#endif
-smsg __ARGS((char_u *, ...));
-int
-#ifdef __BORLANDC__
-_RTLENTRYF
-#endif
-smsg_attr __ARGS((int, char_u *, ...));
-# endif
 # include "memfile.pro"
 # include "memline.pro"
 # ifdef FEAT_MENU
 #  include "menu.pro"
 # endif
+
+# if !defined MESSAGE_FILE || defined(HAVE_STDARG_H)
+    /* These prototypes cannot be produced automatically and conflict with
+     * the old-style prototypes in message.c. */
+int
+#  ifdef __BORLANDC__
+_RTLENTRYF
+#  endif
+smsg __ARGS((char_u *, ...));
+int
+#  ifdef __BORLANDC__
+_RTLENTRYF
+#  endif
+smsg_attr __ARGS((int, char_u *, ...));
+int
+#  ifdef __BORLANDC__
+_RTLENTRYF
+#  endif
+vim_snprintf __ARGS((char *, size_t, char *, ...));
+# endif
+
 # include "message.pro"
 # include "misc1.pro"
 # include "misc2.pro"
diff --git a/src/spell.c b/src/spell.c
index cc2d4fb..2a14da3 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -1332,13 +1332,15 @@
 	else
 #endif
 	    p = (char_u *)"latin1";
-	sprintf((char *)fname_enc, "spell/%s.%s.spl", lang, p);
+	vim_snprintf((char *)fname_enc, sizeof(fname_enc),
+						  "spell/%s.%s.spl", lang, p);
 
 	r = do_in_runtimepath(fname_enc, TRUE, spell_load_file, lp);
 	if (r == FAIL && !lp->sl_error)
 	{
 	    /* Try loading the ASCII version. */
-	    sprintf((char *)fname_enc, "spell/%s.ascii.spl", lang);
+	    vim_snprintf((char *)fname_enc, sizeof(fname_enc),
+						  "spell/%s.ascii.spl", lang);
 
 	    r = do_in_runtimepath(fname_enc, TRUE, spell_load_file, lp);
 	}
@@ -4837,7 +4839,7 @@
     {
 	/* Check for overwriting before doing things that may take a lot of
 	 * time. */
-	sprintf((char *)wfname, "%s.%s.spl", fnames[0],
+	vim_snprintf((char *)wfname, sizeof(wfname), "%s.%s.spl", fnames[0],
 					   ascii ? (char_u *)"ascii" : p_enc);
 	if (!eap->forceit && mch_stat((char *)wfname, &st) >= 0)
 	{
@@ -4887,12 +4889,12 @@
 	{
 	    /* Read the .aff file.  Will init "conv" based on the "SET" line. */
 	    conv.vc_type = CONV_NONE;
-	    sprintf((char *)fname, "%s.aff", fnames[i]);
+	    vim_snprintf((char *)fname, sizeof(fname), "%s.aff", fnames[i]);
 	    if ((afile[i - 1] = spell_read_aff(fname, &conv, ascii)) == NULL)
 		break;
 
 	    /* Read the .dic file. */
-	    sprintf((char *)fname, "%s.dic", fnames[i]);
+	    vim_snprintf((char *)fname, sizeof(fname), "%s.dic", fnames[i]);
 	    if (spell_read_dic(&dfile[i - 1], fname, &conv, ascii) == FAIL)
 		break;