Add strlcat() from OpenBSD, to be used for replacing strncat and other

strange coding practices.

src/bin/pg_config/pg_config.c

@@ -17,7 +17,7 @@
  *
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/pg_config/pg_config.c,v 1.23 2007/01/05 22:19:48 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_config/pg_config.c,v 1.24 2007/02/07 00:28:54 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -213,7 +213,7 @@ show_pgxs(bool all)
 	if (all)
 		printf("PGXS = ");
 	get_pkglib_path(mypath, path);
-	strncat(path, "/pgxs/src/makefiles/pgxs.mk", MAXPGPATH - 1 - strlen(path));
+	strlcat(path, "/pgxs/src/makefiles/pgxs.mk", sizeof(path));
 	cleanup_path(path);
 	printf("%s\n", path);
 }

src/include/pg_config.h.in

@@ -87,6 +87,10 @@
    don't. */
 #undef HAVE_DECL_SNPRINTF
 
+/* Define to 1 if you have the declaration of `strlcat', and to 0 if you
+   don't. */
+#undef HAVE_DECL_STRLCAT
+
 /* Define to 1 if you have the declaration of `strlcpy', and to 0 if you
    don't. */
 #undef HAVE_DECL_STRLCPY
@@ -389,6 +393,9 @@
 /* Define to 1 if you have the <string.h> header file. */
 #undef HAVE_STRING_H
 
+/* Define to 1 if you have the `strlcat' function. */
+#undef HAVE_STRLCAT
+
 /* Define to 1 if you have the `strlcpy' function. */
 #undef HAVE_STRLCPY
 

src/include/port.h

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/port.h,v 1.109 2007/01/19 16:42:24 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/port.h,v 1.110 2007/02/07 00:28:55 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -343,6 +343,10 @@ extern int	inet_aton(const char *cp, struct in_addr * addr);
 extern char *strdup(const char *str);
 #endif
 
+#if !HAVE_DECL_STRLCAT
+extern size_t strlcat(char *dst, const char *src, size_t siz);
+#endif
+
 #if !HAVE_DECL_STRLCPY
 extern size_t strlcpy(char *dst, const char *src, size_t siz);
 #endif

src/port/strlcat.c

@@ -0,0 +1,55 @@
+/*	$OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $	*/
+
+/*
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "c.h"
+
+
+/*
+ * Appends src to string dst of size siz (unlike strncat, siz is the
+ * full size of dst, not space left).  At most siz-1 characters
+ * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
+ * Returns strlen(src) + MIN(siz, strlen(initial dst)).
+ * If retval >= siz, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t siz)
+{
+	char *d = dst;
+	const char *s = src;
+	size_t n = siz;
+	size_t dlen;
+
+	/* Find the end of dst and adjust bytes left but don't go past end */
+	while (n-- != 0 && *d != '\0')
+		d++;
+	dlen = d - dst;
+	n = siz - dlen;
+
+	if (n == 0)
+		return(dlen + strlen(s));
+	while (*s != '\0') {
+		if (n != 1) {
+			*d++ = *s;
+			n--;
+		}
+		s++;
+	}
+	*d = '\0';
+
+	return(dlen + (s - src));	/* count does not include NUL */
+}