From looking at the sources, the $peg parameter appears to be
unused.

Alan, can you confirm that this parameter is indeed unused?

Yes, 

The peg option was removed here - It's probably only in there for BC - the argument is ignored
http://svn.php.net/viewvc/pecl/svn/trunk/svn.c?r1=315262&r2=317303

Committing to SVN seems to not work anymore - here's the patch to fix this.


--- trunk/svn.c	(revision 352318)
+++ trunk/svn.c	(working copy)
@@ -961,7 +961,7 @@
 }
 
 
-/* {{{ proto array svn_ls(string repository_url [, int revision [, bool recurse [, bool peg]]])
+/* {{{ proto array svn_ls(string repository_url [, int revision [, bool recurse ]])
 	Returns a list of a directory in a working copy or repository, optionally at revision_no. */
 PHP_FUNCTION(svn_ls)
 {
@@ -968,7 +968,7 @@
 	const char *repos_url = NULL;
 	const char *utf8_repos_url = NULL;
 	long repos_url_len;
-	zend_bool recurse = 0, peg = 0;
+	zend_bool recurse = 0;
 	svn_error_t *err;
 	svn_opt_revision_t revision = { 0 };
 	apr_hash_t *dirents;
@@ -977,8 +977,8 @@
 	const char *true_path;
 	apr_hash_index_t *hi;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|lbb",
-			&repos_url, &repos_url_len, &revision.value.number, &recurse, &peg) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|lb",
+			&repos_url, &repos_url_len, &revision.value.number, &recurse) == FAILURE) {
 		return;
 	}
 	PHP_SVN_INIT_CLIENT();

Several SVN repos have been moved to Github a while ago.  I just
invited you to <https://github.com/php/pecl-tools-svn>.  I'm
uncomfortable with working on that repo, because I cannot even
build on Windows.