#
#
# add_dir "tests/w_selector"
# 
# add_file "tests/w_selector/__driver__.lua"
#  content [75b6c0ec3c3b50dc651acbc938e08778cc166c32]
# 
# patch "NEWS"
#  from [4185f5904848634aafa6d7b3340df73533bc305c]
#    to [4fb3a20cd2d273bd91109e1937a104f8a1e856c7]
# 
# patch "monotone.texi"
#  from [e3ee512383c619b773f1c7d24acd74ce6b6ad7b1]
#    to [b1ea779ac43cdb91cb9d2423910233493a612453]
# 
# patch "selectors.cc"
#  from [91d924b52e55b60329cba63adac1af6d874014d0]
#    to [9d5b40b5b6930b793c110d0950076556ff182782]
#
============================================================
--- tests/w_selector/__driver__.lua	75b6c0ec3c3b50dc651acbc938e08778cc166c32
+++ tests/w_selector/__driver__.lua	75b6c0ec3c3b50dc651acbc938e08778cc166c32
@@ -0,0 +1,22 @@
+
+include("common/selectors.lua")
+
+mtn_setup()
+
+-- empty revision
+selmap("w:", {""})
+
+-- clean ws
+addfile("testfile", "blah blah")
+commit()
+r=base_revision()
+selmap("w:", {r})
+
+-- ws with changes
+writefile("testfile", "stuff stuff")
+selmap("w:", {r})
+commit()
+
+-- back to parent
+check(mtn("update", "-rp:"), 0, false, false)
+selmap("w:", {r})
============================================================
--- NEWS	4185f5904848634aafa6d7b3340df73533bc305c
+++ NEWS	4fb3a20cd2d273bd91109e1937a104f8a1e856c7
@@ -14,6 +14,9 @@ xxx xxx xx xx:xx:xx UTC 2009
 
         New features
 
+        - New 'w:' selector type for selecting the revision the workspace
+          is based on.
+
         Bugs fixed
 
         Internal
============================================================
--- monotone.texi	e3ee512383c619b773f1c7d24acd74ce6b6ad7b1
+++ monotone.texi	b1ea779ac43cdb91cb9d2423910233493a612453
@@ -2811,6 +2811,10 @@ @heading Selectors in detail
 Uses selector type @code{t}. For example, @code{t:monotone-0.11} matches
 @code{tag} certs where the cert value begins with @code{monotone-0.11}.
 Values to match for can have shell wildcards.
address@hidden Workspace base revision
+Uses selector type @code{w}. This selector must be used from within a
+workspace and must not have any associated value. It matches the base
+revision ID(s) this workspace is based on.
 @end table
 
 Further selector types may be added in the future.
============================================================
--- selectors.cc	91d924b52e55b60329cba63adac1af6d874014d0
+++ selectors.cc	9d5b40b5b6930b793c110d0950076556ff182782
@@ -45,15 +45,15 @@ enum selector_type
     sel_message,
     sel_parent,
     sel_update,
+    sel_base,
     sel_unknown
   };
 
 typedef vector<pair<selector_type, string> > selector_list;
 
 static void
-decode_selector(project_t & project,
-                options const & opts,
-                lua_hooks & lua,
+decode_selector(options const & opts, lua_hooks & lua,
+                project_t & project,
                 string const & orig_sel,
                 selector_type & type,
                 string & sel)
@@ -116,6 +116,9 @@ decode_selector(project_t & project,
         case 'u':
           type = sel_update;
           break;
+        case 'w':
+          type = sel_base;
+          break;
         default:
           W(F("unknown selector type: %c") % sel[0]);
           break;
@@ -214,6 +217,10 @@ decode_selector(project_t & project,
             sel = encode_hexenc(update_id.inner()(), origin::internal);
           }
           break;
+        case sel_base:
+          E(sel.empty(), origin::user,
+            F("no value is allowed with the base revision selector w:"));
+          break;
 
         default: break;
         }
@@ -221,9 +228,8 @@ static void
 }
 
 static void
-parse_selector(project_t & project,
-               options const & opts,
-               lua_hooks & lua,
+parse_selector(options const & opts, lua_hooks & lua,
+               project_t & project,
                string const & str, selector_list & sels)
 {
   sels.clear();
@@ -250,14 +256,15 @@ parse_selector(project_t & project,
           string sel;
           selector_type type = sel_unknown;
 
-          decode_selector(project, opts, lua, *i, type, sel);
+          decode_selector(opts, lua, project,  *i, type, sel);
           sels.push_back(make_pair(type, sel));
         }
     }
 }
 
 static void
-complete_one_selector(project_t & project,
+complete_one_selector(options const & opts, lua_hooks & lua,
+                      project_t & project,
                       selector_type ty, string const & value,
                       set<revision_id> & completions)
 {
@@ -358,11 +365,27 @@ complete_one_selector(project_t & projec
           }
       }
       break;
+
+    case sel_base:
+      {
+        workspace work(opts, lua, F("the selector w: returns the "
+                                    "base revision(s) of the workspace"));
+        parent_map parents;
+        work.get_parent_rosters(project.db, parents);
+
+        for (parent_map::const_iterator i = parents.begin();
+             i != parents.end(); ++i)
+          {
+            completions.insert(i->first);
+          }
+      }
+      break;
     }
 }
 
 static void
-complete_selector(project_t & project,
+complete_selector(options const & opts, lua_hooks & lua,
+                  project_t & project,
                   selector_list const & limit,
                   set<revision_id> & completions)
 {
@@ -373,14 +396,14 @@ complete_selector(project_t & project,
     }
 
   selector_list::const_iterator i = limit.begin();
-  complete_one_selector(project, i->first, i->second, completions);
+  complete_one_selector(opts, lua, project, i->first, i->second, completions);
   i++;
 
   while (i != limit.end())
     {
       set<revision_id> candidates;
       set<revision_id> intersection;
-      complete_one_selector(project, i->first, i->second, candidates);
+      complete_one_selector(opts, lua, project, i->first, i->second, candidates);
 
       intersection.clear();
       set_intersection(completions.begin(), completions.end(),
@@ -399,7 +422,7 @@ complete(options const & opts, lua_hooks
          set<revision_id> & completions)
 {
   selector_list sels;
-  parse_selector(project, opts, lua, str, sels);
+  parse_selector(opts, lua, project, str, sels);
 
   // avoid logging if there's no expansion to be done
   if (sels.size() == 1
@@ -413,7 +436,7 @@ complete(options const & opts, lua_hooks
     }
 
   P(F("expanding selection '%s'") % str);
-  complete_selector(project, sels, completions);
+  complete_selector(opts, lua, project, sels, completions);
 
   E(!completions.empty(), origin::user,
     F("no match for selection '%s'") % str);
@@ -454,7 +477,7 @@ expand_selector(options const & opts, lu
                 set<revision_id> & completions)
 {
   selector_list sels;
-  parse_selector(project, opts, lua, str, sels);
+  parse_selector(opts, lua, project, str, sels);
 
   // avoid logging if there's no expansion to be done
   if (sels.size() == 1
@@ -466,7 +489,7 @@ expand_selector(options const & opts, lu
       return;
     }
 
-  complete_selector(project, sels, completions);
+  complete_selector(opts, lua, project, sels, completions);
 }
 
 void