upgrade to latest upstream TRE regex code (0.8.0)

the main practical results of this change are
1. the regex code is no longer subject to LGPL; it's now 2-clause BSD
2. most (all?) popular nonstandard regex extensions are supported

I hesitate to call this a "sync" since both the old and new code are
heavily modified. in one sense, the old code was "more severely"
modified, in that it was actively hostile to non-strictly-conforming
expressions. on the other hand, the new code has eliminated the
useless translation of the entire regex string to wchar_t prior to
compiling, and now only converts multibyte character literals as
needed.

in the future i may use this modified TRE as a basis for writing the
long-planned new regex engine that will avoid multibyte-to-wide
character conversion entirely by compiling multibyte bracket
expressions specific to UTF-8.

1 files changed, 8 insertions, 48 deletions

diff --git a/src/regex/regerror.c b/src/regex/regerror.c
index 39d70b2a..17119fff 100644
--- a/src/regex/regerror.c
+++ b/src/regex/regerror.c
@@ -1,26 +1,6 @@
-/*
-  regerror.c - POSIX regerror() implementation for TRE.
-
-  Copyright (c) 2001-2006 Ville Laurikari <vl@iki.fi>.
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-
-*/
-
 #include <string.h>
 #include <regex.h>
+#include <stdio.h>
 
 /* Error message strings for error codes listed in `regex.h'.  This list
    needs to be in sync with the codes listed there, naturally. */
@@ -28,7 +8,7 @@
 /* Converted to single string by Rich Felker to remove the need for
  * data relocations at runtime, 27 Feb 2006. */
 
-static const char tre_error_messages[] = {
+static const char messages[] = {
   "No error\0"
   "No match\0"
   "Invalid regexp\0"
@@ -43,33 +23,13 @@ static const char tre_error_messages[] = {
   "Invalid character range\0"
   "Out of memory\0"
   "XXX\0"
+  "\0Unknown error"
 };
 
-size_t
-regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
+size_t regerror(int e, const regex_t *preg, char *buf, size_t size)
 {
-  const char *err;
-  size_t err_len;
-
-  if (errcode >= 0 && errcode <= REG_BADRPT)
-    for (err=tre_error_messages; errcode; errcode--, err+=strlen(err)+1);
-  else
-    err = "Unknown error";
-
-  err_len = strlen(err) + 1;
-  if (errbuf_size > 0 && errbuf != NULL)
-    {
-      if (err_len > errbuf_size)
-	{
-	  memcpy(errbuf, err, errbuf_size - 1);
-	  errbuf[errbuf_size - 1] = '\0';
-	}
-      else
-	{
-	  strcpy(errbuf, err);
-	}
-    }
-  return err_len;
+	const char *s;
+	for (s=messages; e && *s; e--, e+=strlen(s)+1);
+	if (!*s) s++;
+	return 1+snprintf(buf, size, "%s", s);
 }
-
-/* EOF */