#
#
# patch "database.cc"
#  from [7249d3009e36b16ea76cd5140258a64a2f49f4ac]
#    to [22e4b9ab811ee3efcd5a166a67094e259ea8190a]
# 
# patch "database.hh"
#  from [3f70833f9928db8ea4e9e944246318d21dcd341d]
#    to [5d4aef04a21ec365ba5aa77082d0dd83d915aaef]
# 
# patch "outdated_indicator.cc"
#  from [ba676108726aaf7eba3b7e7e357165696e15a599]
#    to [d2a291d777cf8fc623aba344f077260aa5f6640d]
# 
# patch "outdated_indicator.hh"
#  from [8f8a6bd36595e3c846be40ad59f550983a00f2a0]
#    to [8e9f3eda60d383421cf8e280722f83aada2ca29a]
# 
# patch "project.cc"
#  from [1b6e35dad7b01bd6ba5561c2ccad1a330beb1684]
#    to [7f09669ff03f52d03219582eb0885e66fee42c57]
# 
# patch "project.hh"
#  from [617e7b94d34649ffe5ea90f1d5e783ba0c7260c8]
#    to [a2f4dd3608d0bb80168a5aa41cef110a3f0c3af9]
#
============================================================
--- database.cc	7249d3009e36b16ea76cd5140258a64a2f49f4ac
+++ database.cc	22e4b9ab811ee3efcd5a166a67094e259ea8190a
@@ -3936,7 +3936,7 @@ namespace {
   // the lua hook wants key_identity_info, but all that's been
   // pulled from the certs is key_id. So this is needed to translate.
   // use pointers for project and lua so bind() doesn't make copies
-  bool check_revision_cert_trust(project_t * const project,
+  bool check_revision_cert_trust(project_t const * const project,
                                  lua_hooks * const lua,
                                  set<key_id> const & signers,
                                  id const & hash,
@@ -3980,7 +3980,7 @@ void
 } // anonymous namespace
 
 void
-database::erase_bogus_certs(project_t & project, vector<cert> & certs)
+database::erase_bogus_certs(project_t const & project, vector<cert> & certs)
 {
   erase_bogus_certs_internal(certs, *this,
                              boost::bind(&check_revision_cert_trust,
============================================================
--- database.hh	3f70833f9928db8ea4e9e944246318d21dcd341d
+++ database.hh	5d4aef04a21ec365ba5aa77082d0dd83d915aaef
@@ -344,7 +344,7 @@ public:
                                cert_name const &,
                                cert_value const &)> cert_trust_checker;
   // this takes a project_t so it can translate key names for the trust hook
-  void erase_bogus_certs(project_t & project, std::vector<cert> & certs);
+  void erase_bogus_certs(project_t const & project, std::vector<cert> & certs);
   // permit alternative trust functions
   void erase_bogus_certs(std::vector<cert> & certs,
                          cert_trust_checker const & checker);
============================================================
--- outdated_indicator.cc	ba676108726aaf7eba3b7e7e357165696e15a599
+++ outdated_indicator.cc	d2a291d777cf8fc623aba344f077260aa5f6640d
@@ -58,7 +58,7 @@ bool
 {}
 
 bool
-outdated_indicator::outdated()
+outdated_indicator::outdated() const
 {
   if (parent)
     {
============================================================
--- outdated_indicator.hh	8f8a6bd36595e3c846be40ad59f550983a00f2a0
+++ outdated_indicator.hh	8e9f3eda60d383421cf8e280722f83aada2ca29a
@@ -33,7 +33,7 @@ public:
 public:
   outdated_indicator();
   explicit outdated_indicator(boost::shared_ptr<outdated_indicator_factory_impl> p);
-  bool outdated();
+  bool outdated() const;
 };
 
 
============================================================
--- project.cc	1b6e35dad7b01bd6ba5561c2ccad1a330beb1684
+++ project.cc	7f09669ff03f52d03219582eb0885e66fee42c57
@@ -62,7 +62,7 @@ project_t::get_branch_list(set<branch_na
 
 void
 project_t::get_branch_list(set<branch_name> & names,
-                           bool check_heads)
+                           bool check_heads) const
 {
   if (indicator.outdated())
     {
@@ -92,7 +92,7 @@ project_t::get_branch_list(globish const
 void
 project_t::get_branch_list(globish const & glob,
                            set<branch_name> & names,
-                           bool check_heads)
+                           bool check_heads) const
 {
   vector<string> got;
   db.get_branches(glob, got);
@@ -118,9 +118,9 @@ namespace
 {
   struct not_in_branch : public is_failure
   {
-    project_t & project;
+    project_t const & project;
     branch_name const & branch;
-    not_in_branch(project_t & project,
+    not_in_branch(project_t const & project,
                   branch_name const & branch)
       : project(project), branch(branch)
     {}
@@ -138,9 +138,9 @@ namespace
 
   struct suspended_in_branch : public is_failure
   {
-    project_t & project;
+    project_t const & project;
     branch_name const & branch;
-    suspended_in_branch(project_t & project,
+    suspended_in_branch(project_t const & project,
                         branch_name const & branch)
       : project(project), branch(branch)
     {}
@@ -161,7 +161,7 @@ project_t::get_branch_heads(branch_name 
 project_t::get_branch_heads(branch_name const & name,
                             set<revision_id> & heads,
                             bool ignore_suspend_certs,
-                            multimap<revision_id, revision_id> * inverse_graph_cache_ptr)
+                            multimap<revision_id, revision_id> * inverse_graph_cache_ptr) const
 {
   pair<branch_name, suspended_indicator>
     cache_index(name, ignore_suspend_certs);
@@ -223,7 +223,7 @@ project_t::revision_is_in_branch(revisio
 
 bool
 project_t::revision_is_in_branch(revision_id const & id,
-                                 branch_name const & branch)
+                                 branch_name const & branch) const
 {
   vector<cert> certs;
   db.get_revision_certs(id, branch_cert_name,
@@ -252,7 +252,7 @@ project_t::revision_is_suspended_in_bran
 
 bool
 project_t::revision_is_suspended_in_branch(revision_id const & id,
-                                 branch_name const & branch)
+                                           branch_name const & branch) const
 {
   vector<cert> certs;
   db.get_revision_certs(id, suspend_cert_name,
@@ -282,14 +282,14 @@ project_t::get_revision_cert_hashes(revi
 
 outdated_indicator
 project_t::get_revision_cert_hashes(revision_id const & rid,
-                                    vector<id> & hashes)
+                                    vector<id> & hashes) const
 {
   return db.get_revision_certs(rid, hashes);
 }
 
 outdated_indicator
 project_t::get_revision_certs(revision_id const & id,
-                              vector<cert> & certs)
+                              vector<cert> & certs) const
 {
   return db.get_revision_certs(id, certs);
 }
@@ -297,7 +297,7 @@ project_t::get_revision_certs_by_name(re
 outdated_indicator
 project_t::get_revision_certs_by_name(revision_id const & id,
                                       cert_name const & name,
-                                      vector<cert> & certs)
+                                      vector<cert> & certs) const
 {
   outdated_indicator i = db.get_revision_certs(id, name, certs);
   db.erase_bogus_certs(*this, certs);
@@ -306,7 +306,7 @@ project_t::get_revision_branches(revisio
 
 outdated_indicator
 project_t::get_revision_branches(revision_id const & id,
-                                 set<branch_name> & branches)
+                                 set<branch_name> & branches) const
 {
   vector<cert> certs;
   outdated_indicator i = get_revision_certs_by_name(id, branch_cert_name, certs);
@@ -320,7 +320,7 @@ project_t::get_branch_certs(branch_name 
 
 outdated_indicator
 project_t::get_branch_certs(branch_name const & branch,
-                            vector<pair<id, cert> > & certs)
+                            vector<pair<id, cert> > & certs) const
 {
   return db.get_revision_certs(branch_cert_name,
                                typecast_vocab<cert_value>(branch), certs);
@@ -351,7 +351,7 @@ outdated_indicator
 }
 
 outdated_indicator
-project_t::get_tags(set<tag_t> & tags)
+project_t::get_tags(set<tag_t> & tags) const
 {
   vector<cert> certs;
   outdated_indicator i = db.get_revision_certs(tag_cert_name, certs);
@@ -485,7 +485,7 @@ project_t::lookup_key_by_name(key_store 
 project_t::lookup_key_by_name(key_store * const keys,
                               lua_hooks & lua,
                               key_name const & name,
-                              key_id & id)
+                              key_id & id) const
 {
   set<key_id> ks_match_by_local_name;
   set<key_id> db_match_by_local_name;
@@ -568,7 +568,7 @@ project_t::get_given_name_of_key(key_sto
 void
 project_t::get_given_name_of_key(key_store * const keys,
                                  key_id const & id,
-                                 key_name & name)
+                                 key_name & name) const
 {
   if (keys && keys->key_pair_exists(id))
     {
@@ -590,7 +590,7 @@ project_t::complete_key_identity_from_id
 void
 project_t::complete_key_identity_from_id(key_store * const keys,
                                          lua_hooks & lua,
-                                         key_identity_info & info)
+                                         key_identity_info & info) const
 {
   MM(info.id);
   MM(info.official_name);
@@ -603,14 +603,14 @@ project_t::complete_key_identity_from_id
 void
 project_t::complete_key_identity_from_id(key_store & keys,
                                          lua_hooks & lua,
-                                         key_identity_info & info)
+                                         key_identity_info & info) const
 {
   complete_key_identity_from_id(&keys, lua, info);
 }
 
 void
 project_t::complete_key_identity_from_id(lua_hooks & lua,
-                                         key_identity_info & info)
+                                         key_identity_info & info) const
 {
   complete_key_identity_from_id(0, lua, info);
 }
@@ -619,7 +619,7 @@ project_t::get_key_identity(key_store * 
 project_t::get_key_identity(key_store * const keys,
                             lua_hooks & lua,
                             external_key_name const & input,
-                            key_identity_info & output)
+                            key_identity_info & output) const
 {
   try
     {
@@ -645,7 +645,7 @@ project_t::get_key_identity(key_store & 
 project_t::get_key_identity(key_store & keys,
                             lua_hooks & lua,
                             external_key_name const & input,
-                            key_identity_info & output)
+                            key_identity_info & output) const
 {
   get_key_identity(&keys, lua, input, output);
 }
@@ -653,7 +653,7 @@ project_t::get_key_identity(lua_hooks & 
 void
 project_t::get_key_identity(lua_hooks & lua,
                             external_key_name const & input,
-                            key_identity_info & output)
+                            key_identity_info & output) const
 {
   get_key_identity(0, lua, input, output);
 }
@@ -662,7 +662,7 @@ project_t::get_key_identity(key_store & 
 project_t::get_key_identity(key_store & keys,
                             lua_hooks & lua,
                             arg_type const & input,
-                            key_identity_info & output)
+                            key_identity_info & output) const
 {
   get_key_identity(&keys, lua, typecast_vocab<external_key_name>(input), output);
 }
@@ -670,7 +670,7 @@ project_t::get_key_identity(lua_hooks & 
 void
 project_t::get_key_identity(lua_hooks & lua,
                             arg_type const & input,
-                            key_identity_info & output)
+                            key_identity_info & output) const
 {
   get_key_identity(0, lua, typecast_vocab<external_key_name>(input), output);
 }
============================================================
--- project.hh	617e7b94d34649ffe5ea90f1d5e783ba0c7260c8
+++ project.hh	a2f4dd3608d0bb80168a5aa41cef110a3f0c3af9
@@ -59,8 +59,8 @@ public:
 class tag_t
 {
 public:
-  revision_id ident;
-  utf8 name;
+  revision_id const ident;
+  utf8 const name;
   key_id key;
   tag_t(revision_id const & ident, utf8 const & name, key_id const & key);
 };
@@ -80,47 +80,50 @@ private:
   database & db;
 
 private:
-  std::map<std::pair<branch_name, suspended_indicator>,
-           std::pair<outdated_indicator, std::set<revision_id> >
-           > branch_heads;
-  std::set<branch_name> branches;
-  outdated_indicator indicator;
+  // These are caches of what's in the database. They are updated when
+  // they're noticed to be out of date, which will always be during a
+  // logically read-only operation.
+  mutable std::map<std::pair<branch_name, suspended_indicator>,
+                   std::pair<outdated_indicator, std::set<revision_id> >
+                   > branch_heads;
+  mutable std::set<branch_name> branches;
+  mutable outdated_indicator indicator;
 
 public:
   project_t(database & db);
 
   void get_branch_list(std::set<branch_name> & names,
-                       bool check_heads = false);
+                       bool check_heads = false) const;
   void get_branch_list(globish const & glob, std::set<branch_name> & names,
-                       bool check_heads = false);
+                       bool check_heads = false) const;
   void get_branch_heads(branch_name const & name, std::set<revision_id> & heads,
                         bool ignore_suspend_certs,
-                        std::multimap<revision_id, revision_id> *inverse_graph_cache_ptr = NULL);
+                        std::multimap<revision_id, revision_id> *inverse_graph_cache_ptr = NULL) const;
 
-  outdated_indicator get_tags(std::set<tag_t> & tags);
+  outdated_indicator get_tags(std::set<tag_t> & tags) const;
   void put_tag(key_store & keys, revision_id const & id, std::string const & name);
 
-  bool revision_is_in_branch(revision_id const & id, branch_name const & branch);
+  bool revision_is_in_branch(revision_id const & id, branch_name const & branch) const;
   void put_revision_in_branch(key_store & keys,
                               revision_id const & id,
                               branch_name const & branch);
 
-  bool revision_is_suspended_in_branch(revision_id const & id, branch_name const & branch);
+  bool revision_is_suspended_in_branch(revision_id const & id, branch_name const & branch) const;
   void suspend_revision_in_branch(key_store & keys,
                                   revision_id const & id,
                                   branch_name const & branch);
 
   outdated_indicator get_revision_cert_hashes(revision_id const & rid,
-                                              std::vector<id> & hashes);
+                                              std::vector<id> & hashes) const;
   outdated_indicator get_revision_certs(revision_id const & id,
-                                        std::vector<cert> & certs);
+                                        std::vector<cert> & certs) const;
   outdated_indicator get_revision_certs_by_name(revision_id const & id,
                                                 cert_name const & name,
-                                                std::vector<cert> & certs);
+                                                std::vector<cert> & certs) const;
   outdated_indicator get_revision_branches(revision_id const & id,
-                                           std::set<branch_name> & branches);
+                                           std::set<branch_name> & branches) const;
   outdated_indicator get_branch_certs(branch_name const & branch,
-                                      std::vector<std::pair<id, cert> > & certs);
+                                      std::vector<std::pair<id, cert> > & certs) const;
 
   void put_standard_certs(key_store & keys,
                           revision_id const & id,
@@ -153,38 +156,38 @@ private:
   void lookup_key_by_name(key_store * const keys,
                           lua_hooks & lua,
                           key_name const & name,
-                          key_id & id);
+                          key_id & id) const;
   // get the name given when creating the key
   void get_given_name_of_key(key_store * const keys,
                              key_id const & id,
-                             key_name & name);
+                             key_name & name) const;
   void complete_key_identity_from_id(key_store * const keys,
                                      lua_hooks & lua,
-                                     key_identity_info & info);
+                                     key_identity_info & info) const;
   void get_key_identity(key_store * const keys,
                         lua_hooks & lua,
                         external_key_name const & input,
-                        key_identity_info & output);
+                        key_identity_info & output) const;
 public:
   void complete_key_identity_from_id(key_store & keys,
                                      lua_hooks & lua,
-                                     key_identity_info & info);
+                                     key_identity_info & info) const;
   void complete_key_identity_from_id(lua_hooks & lua,
-                                     key_identity_info & info);
+                                     key_identity_info & info) const;
   void get_key_identity(key_store & keys,
                         lua_hooks & lua,
                         external_key_name const & input,
-                        key_identity_info & output);
+                        key_identity_info & output) const;
   void get_key_identity(lua_hooks & lua,
                         external_key_name const & input,
-                        key_identity_info & output);
+                        key_identity_info & output) const;
   void get_key_identity(key_store & keys,
                         lua_hooks & lua,
                         arg_type const & input,
-                        key_identity_info & output);
+                        key_identity_info & output) const;
   void get_key_identity(lua_hooks & lua,
                         arg_type const & input,
-                        key_identity_info & output);
+                        key_identity_info & output) const;
 };
 
 std::string