[StGIT PATCH] Don't use patches/<branch>/current

["Karl Hasselström" <kha@treskal.com>]

The name of the current patch, if any, is always the last line of
patches/<branch>/applied (and there is no current patch if and only if
the "applied" file is empty). So use that instead, and stop having to
worry about keeping the redundant "current" file up-to-date.

Signed-off-by: Karl Hasselström <kha@treskal.com>
---

This is another remove-redundant-metadata cleanup patch. Not only does
it remove more code than it adds, the removed code (mostly calls to
__set_current) is the kind that one easily forgets to insert in the
proper places when writing new code.

 stgit/stack.py |   35 +++++++++--------------------------
 1 files changed, 9 insertions(+), 26 deletions(-)

diff --git a/stgit/stack.py b/stgit/stack.py
index 2477ac6..3e9fc4f 100644
--- a/stgit/stack.py
+++ b/stgit/stack.py
@@ -295,7 +295,6 @@ class Series(StgitObject):
         self.__applied_file = os.path.join(self._dir(), 'applied')
         self.__unapplied_file = os.path.join(self._dir(), 'unapplied')
         self.__hidden_file = os.path.join(self._dir(), 'hidden')
-        self.__current_file = os.path.join(self._dir(), 'current')
         self.__descr_file = os.path.join(self._dir(), 'description')
 
         # where this series keeps its patches
@@ -325,11 +324,6 @@ class Series(StgitObject):
         """
         return self.__name
 
-    def __set_current(self, name):
-        """Sets the topmost patch
-        """
-        self._set_field('current', name)
-
     def get_patch(self, name):
         """Return a Patch object for the given name
         """
@@ -346,11 +340,16 @@ class Series(StgitObject):
     def get_current(self):
         """Return the name of the topmost patch, or None if there is
         no such patch."""
-        name = self._get_field('current')
-        if name == '':
+        try:
+            applied = self.get_applied()
+        except StackException:
+            # No "applied" file: branch is not initialized.
+            return None
+        try:
+            return applied[-1]
+        except IndexError:
+            # No patches applied.
             return None
-        else:
-            return name
 
     def get_applied(self):
         if not os.path.isfile(self.__applied_file):
@@ -650,8 +649,6 @@ class Series(StgitObject):
                 os.remove(self.__unapplied_file)
             if os.path.exists(self.__hidden_file):
                 os.remove(self.__hidden_file)
-            if os.path.exists(self.__current_file):
-                os.remove(self.__current_file)
             if os.path.exists(self.__descr_file):
                 os.remove(self.__descr_file)
             if os.path.exists(self._dir()+'/orig-base'):
@@ -825,11 +822,8 @@ class Series(StgitObject):
             self.log_patch(patch, 'new')
 
             insert_string(self.__applied_file, patch.get_name())
-            if not self.get_current():
-                self.__set_current(name)
         else:
             append_string(self.__applied_file, patch.get_name())
-            self.__set_current(name)
             if refresh:
                 self.refresh_patch(cache_update = False, log = 'new')
 
@@ -936,8 +930,6 @@ class Series(StgitObject):
         f.writelines([line + '\n' for line in unapplied])
         f.close()
 
-        self.__set_current(name)
-
         return forwarded
 
     def merged_patches(self, names):
@@ -1019,8 +1011,6 @@ class Series(StgitObject):
         f.writelines([line + '\n' for line in unapplied])
         f.close()
 
-        self.__set_current(name)
-
         # head == bottom case doesn't need to refresh the patch
         if empty or head != bottom:
             if not ex:
@@ -1098,11 +1088,6 @@ class Series(StgitObject):
         f.writelines([line + '\n' for line in applied])
         f.close()
 
-        if applied == []:
-            self.__set_current(None)
-        else:
-            self.__set_current(applied[-1])
-
     def empty_patch(self, name):
         """Returns True if the patch is empty
         """
@@ -1144,8 +1129,6 @@ class Series(StgitObject):
             f.close()
         elif oldname in applied:
             Patch(oldname, self.__patch_dir, self.__refs_dir).rename(newname)
-            if oldname == self.get_current():
-                self.__set_current(newname)
 
             applied[applied.index(oldname)] = newname