tparm() now returns NULL for buffers that would be >= 256 (termcap

size limit).  Also, make _tparm take a size argument.  This isn't
strictly necesary as we know the size of the buffer and this function
is only used internally but this has the added benefit of making
_tparm == GNU tparam if we ever want to export it as such.  There
are reported to be problems with emacs when native libtermlib has
tparam() so we keep this private for now.

1 files changed, 34 insertions, 32 deletions

diff --git a/lib/libtermlib/tparm.c b/lib/libtermlib/tparm.c
index 0b545a77f10..082c480543e 100644
--- a/lib/libtermlib/tparm.c
+++ b/lib/libtermlib/tparm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tparm.c,v 1.5 1997/07/25 20:30:26 mickey Exp $	*/
+/*	$OpenBSD: tparm.c,v 1.6 1997/12/16 03:10:05 millert Exp $	*/
 
 /*
  * Copyright (c) 1996 SigmaSoft, Th. Lockert <tholo@sigmasoft.com>
@@ -31,7 +31,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$OpenBSD: tparm.c,v 1.5 1997/07/25 20:30:26 mickey Exp $";
+static char rcsid[] = "$OpenBSD: tparm.c,v 1.6 1997/12/16 03:10:05 millert Exp $";
 #endif
 
 #include <stdio.h>
@@ -57,7 +57,7 @@ static __inline void push __P((int));
 static __inline int popnum __P((void));
 static __inline char *popstr __P((void));
 
-static char *_tparm __P((const char *, char *, va_list));
+static char *_tparm __P((const char *, char *, size_t, va_list));
 
 static union {
     unsigned int	num;
@@ -86,10 +86,15 @@ popstr()
     return stackidx > 0 ? stack[--stackidx].str : NULL;
 }
 
+/*
+ * This function is identical to the GNU tparam() but we don't
+ * advertise it as such since it confuses emacs (and perhaps others).
+ */
 static char *
-_tparm(str, buf, ap)
+_tparm(str, buf, siz, ap)
      const char *str;
      char *buf;
+     size_t siz;
      va_list ap;
 {
     int param[10], variable[26];
@@ -138,21 +143,21 @@ _tparm(str, buf, ap)
 
     while (*str) {
 	if (*str != '%') {
-	    if (bufp >= buf + MAXRETURNSIZE)
-		goto overflow;
+	    if (bufp >= buf + siz)
+		return(NULL);
 	    *bufp++ = *str;
 	}
 	else {
 	    switch (*++str) {
 		case '%':
-		    if (bufp >= buf + MAXRETURNSIZE)
-			goto overflow;
+		    if (bufp >= buf + siz)
+			return(NULL);
 		    *bufp++ = '%';
 		    break;
 		case 'd':
 		    sprintf(scratch, "%d", popnum());
-		    if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-			goto overflow;
+		    if (bufp + strlen(scratch) >= buf + siz)
+			return(NULL);
 		    strcpy(bufp, scratch);
 		    bufp += strlen(bufp);
 		    break;
@@ -164,8 +169,8 @@ _tparm(str, buf, ap)
 				sprintf(scratch, "%02d", popnum());
 			    else
 				sprintf(scratch, "%03d", popnum());
-			    if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-				goto overflow;
+			    if (bufp + strlen(scratch) >= buf + siz)
+				return(NULL);
 			    strcpy(bufp, scratch);
 			    bufp += strlen(bufp);
 			}
@@ -174,8 +179,8 @@ _tparm(str, buf, ap)
 				sprintf(scratch, "%02x", popnum());
 			    else
 				sprintf(scratch, "%03x", popnum());
-			    if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-				goto overflow;
+			    if (bufp + strlen(scratch) >= buf + siz)
+				return(NULL);
 			    strcpy(bufp, scratch);
 			    bufp += strlen(bufp);
 			}
@@ -184,15 +189,15 @@ _tparm(str, buf, ap)
 		case '2':
 		    if (*++str == 'd') {
 			sprintf(scratch, "%2d", popnum());
-			if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-			    goto overflow;
+			if (bufp + strlen(scratch) >= buf + siz)
+			    return(NULL);
 			strcpy(bufp, scratch);
 			bufp += strlen(bufp);
 		    }
 		    else if (*str == 'x') {
 			sprintf(scratch, "%2x", popnum());
-			if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-			    goto overflow;
+			if (bufp + strlen(scratch) >= buf + siz)
+			    return(NULL);
 			strcpy(bufp, scratch);
 			bufp += strlen(bufp);
 		    }
@@ -200,27 +205,27 @@ _tparm(str, buf, ap)
 		case '3':
 		    if (*++str == 'd') {
 			sprintf(scratch, "%3d", popnum());
-			if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-			    goto overflow;
+			if (bufp + strlen(scratch) >= buf + siz)
+			    return(NULL);
 			strcpy(bufp, scratch);
 			bufp += strlen(bufp);
 		    }
 		    else if (*str == 'x') {
 			sprintf(scratch, "%3x", popnum());
-			if (bufp + strlen(scratch) >= buf + MAXRETURNSIZE)
-			    goto overflow;
+			if (bufp + strlen(scratch) >= buf + siz)
+			    return(NULL);
 			strcpy(bufp, scratch);
 			bufp += strlen(bufp);
 		    }
 		    break;
 		case 'c':
-		    if (bufp >= buf + MAXRETURNSIZE)
-			goto overflow;
+		    if (bufp >= buf + siz)
+			return(NULL);
 		    *bufp++ = (char)popnum();
 		    break;
 		case 's':
-		    if (bufp + strlen(p = popstr()) >= buf + MAXRETURNSIZE)
-			goto overflow;
+		    if (bufp + strlen(p = popstr()) >= buf + siz)
+			return(NULL);
 		    strcpy(bufp, p);
 		    bufp += strlen(bufp);
 		    break;
@@ -356,13 +361,10 @@ _tparm(str, buf, ap)
 	    str++;
     }
 
-    if (bufp >= buf + MAXRETURNSIZE)
-	goto overflow;
+    if (bufp >= buf + siz)
+	return(NULL);
     *bufp = '\0';
     return(buf);
-overflow:
-    strcpy(buf, "OVERFLOW!");
-    return(buf);
 }
 
 char *
@@ -385,7 +387,7 @@ tparm(va_alist)
     /* LINTED pointer casts may be troublesome */
     va_start(ap, str);
 #endif
-    p = _tparm(str, buf, ap);
+    p = _tparm(str, buf, sizeof(buf), ap);
     /* LINTED expression has no effect */
     va_end(ap);
     return(p);