Index: subversion/include/private/svn_opt_private.h
===================================================================
--- subversion/include/private/svn_opt_private.h	(revision 30798)
+++ subversion/include/private/svn_opt_private.h	(working copy)
@@ -34,7 +34,7 @@
  *   - check that only valid URI characters remain
  *   - check that no back-path ("..") components are present
  *   - canonicalize the separator ("/") characters
- * URL_IN is in UTF-8 encoding and has no peg revision specifier.
+ * URL_IN is in UTF-8 encoding and can have a peg revision specifier.
  * Set *URL_OUT to the result, allocated from POOL.
  */
 svn_error_t *
@@ -50,7 +50,7 @@
  *   - If the path does not exist (which is valid) the given capitialization
  *     is used.
  *   - canonicalize the separator ("/") characters
- * PATH_IN is in UTF-8 encoding and has no peg revision specifier.
+ * PATH_IN is in UTF-8 encoding and can have a peg revision specifier.
  * Set *PATH_OUT to the result, allocated from POOL.
  */
 svn_error_t *
Index: subversion/libsvn_subr/opt.c
===================================================================
--- subversion/libsvn_subr/opt.c	(revision 30798)
+++ subversion/libsvn_subr/opt.c	(working copy)
@@ -1114,14 +1083,75 @@
   return SVN_NO_ERROR;
 }
 
+/* Extract the peg revision, if any, from UTF8_TARGET. Return the
+ * peg revision in *PEG_REVISION and the true target portion
+ * in *TRUE_TARGET.
+ *
+ * This is needed so that UTF8_TARGET can be properly canonicalized,
+ * otherwise the canonicalization does not treat a ".@BASE" as a "."
+ * with a BASE peg revision, and it is not canonicalized to "@BASE".
+ * If any peg revision exists, it is appended to the final
+ * canonicalized path or URL.  Do not use svn_opt_parse_path()
+ * because the resulting peg revision is a structure that would have
+ * to be converted back into a string.  Converting from a string date
+ * to the apr_time_t field in the svn_opt_revision_value_t and back to
+ * a string would not necessarily preserve the exact bytes of the
+ * input date, so its easier just to keep it in string form.
+ *
+ * All allocations are done in POOL.
+ */
+static svn_error_t *
+split_arg_at_peg_revision(const char **true_target,
+                          const char **peg_revision,
+                          const char *utf8_target,
+                          apr_pool_t *pool)
+{
+  const char *peg_start = NULL; /* pointer to the peg revision, if any */
+  int j;
+
+  for (j = (strlen(utf8_target) - 1); j >= 0; --j)
+    {
+      /* If we hit a path separator, stop looking.  This is OK
+          only because our revision specifiers can't contain
+          '/'. */
+      if (utf8_target[j] == '/')
+        break;
+      if (utf8_target[j] == '@')
+        {
+          peg_start = utf8_target + j;
+          break;
+        }
+    }
+
+  if (peg_start)
+    {
+      *true_target = apr_pstrmemdup(pool,
+                                    utf8_target,
+                                    peg_start - utf8_target);
+
+      *peg_revision = apr_pstrdup(pool, peg_start);
+    }
+  else
+    {
+      *true_target = utf8_target;
+
+      *peg_revision = NULL;
+    }
+
+  return SVN_NO_ERROR;
+}
+
 svn_error_t *
 svn_opt__arg_canonicalize_url(const char **url_out, const char *url_in,
                               apr_pool_t *pool)
 {
   const char *target;
+  const char *peg_rev;
 
+  SVN_ERR(split_arg_at_peg_revision(&target, &peg_rev, url_in, pool));
+
   /* Convert to URI. */
-  target = svn_path_uri_from_iri(url_in, pool);
+  target = svn_path_uri_from_iri(target, pool);
   /* Auto-escape some ASCII characters. */
   target = svn_path_uri_autoescape(target, pool);
 
@@ -1140,6 +1170,11 @@
   /* strip any trailing '/' and collapse other redundant elements */
   target = svn_path_canonicalize(target, pool);
 
+  /* Append the peg revision back to the canonicalized target if
+     there was a peg revision. */
+  if (peg_rev)
+    target = apr_pstrcat(pool, target, peg_rev, NULL);
+
   *url_out = target;
   return SVN_NO_ERROR;
 }
@@ -1151,9 +1186,12 @@
   const char *apr_target;
   char *truenamed_target; /* APR-encoded */
   apr_status_t apr_err;
+  const char *peg_rev;
 
+  SVN_ERR(split_arg_at_peg_revision(&apr_target, &peg_rev, path_in, pool));
+
   /* canonicalize case, and change all separators to '/'. */
-  SVN_ERR(svn_path_cstring_from_utf8(&apr_target, path_in, pool));
+  SVN_ERR(svn_path_cstring_from_utf8(&apr_target, apr_target, pool));
   apr_err = apr_filepath_merge(&truenamed_target, "", apr_target,
                                APR_FILEPATH_TRUENAME, pool);
 
@@ -1174,6 +1212,11 @@
   SVN_ERR(svn_path_cstring_to_utf8(path_out, apr_target, pool));
   *path_out = svn_path_canonicalize(*path_out, pool);
 
+  /* Append the peg revision back to the canonicalized target if
+     there was a peg revision. */
+  if (peg_rev)
+    *path_out = apr_pstrcat(pool, *path_out, peg_rev, NULL);
+
   return SVN_NO_ERROR;
 }