Index: build/generator/swig/header_wrappers.py
===================================================================
--- build/generator/swig/header_wrappers.py	(revision 16643)
+++ build/generator/swig/header_wrappers.py	(working copy)
@@ -103,10 +103,12 @@
   _re_includes = re.compile(r'#\s*include\s*[<"]([^<">;\s]+)')
 
   """Regular expression for parsing structs from a C header file"""
-  _re_structs = re.compile(r'\btypedef\s+struct\s+(svn_[a-z_0-9]+_t)\b\s*(\{?)')
+  _re_structs = re.compile(r'\btypedef\s+(?:struct|union)\s+'
+                           r'(svn_[a-z_0-9]+)\b\s*(\{?)')
 
   """Regular expression for parsing callbacks from a C header file"""
-  _re_callbacks = re.compile(r'\btypedef\s+struct\s+(svn_[a-z_0-9]+_t)\b|'
+  _re_callbacks = re.compile(r'\btypedef\s+(?:struct|union)\s+'
+                             r'(svn_[a-z_0-9]+)\b|'
                              r'\n\s*svn_error_t\s*\*\(\*(\w+)\)\s*\(([^)]+)\);')
 
   """Regular expression for parsing parameter names from a parameter list"""
Index: subversion/include/svn_opt.h
===================================================================
--- subversion/include/svn_opt.h	(revision 16643)
+++ subversion/include/svn_opt.h	(working copy)
@@ -201,15 +201,20 @@
   svn_opt_revision_head
 };
 
+/**
+ * A revision value, which can be stored in one of @c svn_opt_revision_kind
+ * ways. 
+ */
+typedef union svn_opt_revision_value {
+  svn_revnum_t number;
+  apr_time_t date;
+} svn_opt_revision_value;
 
 /** A revision, specified in one of @c svn_opt_revision_kind ways. */
 typedef struct svn_opt_revision_t
 {
   enum svn_opt_revision_kind kind;  /**< See svn_opt_revision_kind */
-  union {
-    svn_revnum_t number;
-    apr_time_t date;
-  } value;                          /**< Extra data qualifying the @c kind */
+  svn_opt_revision_value value;     /**< Extra data qualifying the @c kind */
 } svn_opt_revision_t;
 
 
Index: subversion/bindings/swig/python/tests/pool.py
===================================================================
--- subversion/bindings/swig/python/tests/pool.py	(revision 16643)
+++ subversion/bindings/swig/python/tests/pool.py	(working copy)
@@ -68,9 +68,11 @@
     """Check that integer struct members work correctly"""
  
     # Test good integer assignment operations
-    head_revision = svn.core.svn_opt_revision_t()
-    head_revision.kind = svn.core.svn_opt_revision_head
-    self.assertEqual(head_revision.kind, svn.core.svn_opt_revision_head)
+    rev = svn.core.svn_opt_revision_t()
+    rev.kind = svn.core.svn_opt_revision_number
+    rev.value.number = 10
+    self.assertEqual(rev.kind, svn.core.svn_opt_revision_number)
+    self.assertEqual(rev.value.number, 10)
 
     # Test bad integer assignment operations
     def test_bad_assignment(self):