[PATCH] Factorize VC constructor code

[Vincent Legoll <vincent legoll gmail com>]

The attached patch should be a no-op, behavior-wise
and remove some duplicated code in VC constructors.

CVS, RCS & SVN, now don't need one any more.

The remaining specific constructors are:
- git: handle tree cache, GIT_DIR
- monotone: tree cache, find mtn version
 - bzr, darcs, tla: tree cache

They now use super() to get access to parent's
constructor.

I'll remove the tree-cache need next.

-- 
Vincent Legoll

Index: vc/cvs.py
===================================================================
--- vc/cvs.py	(revision 1326)
+++ vc/cvs.py	(working copy)
@@ -33,13 +33,9 @@
     CMD = "cvs"
     NAME = "CVS"
     VC_DIR = "CVS"
+    VC_ROOT_WALK = False
     PATCH_INDEX_RE = "^Index:(.*)$"
 
-    def __init__(self, location):
-        if not os.path.isdir(os.path.join(location, self.VC_DIR)):
-            raise ValueError
-        self.root = location
-
     def commit_command(self, message):
         return [self.CMD,"commit","-m",message]
     def diff_command(self):
Index: vc/darcs.py
===================================================================
--- vc/darcs.py	(revision 1326)
+++ vc/darcs.py	(working copy)
@@ -43,7 +43,7 @@
 
     def __init__(self, location):
         self._cached_statuses = None
-        _vc.Vc.__init__(self, location)
+        super(Vc, self).__init__(location)
 
     def commit_command(self, message):
         return [self.CMD, "record",
Index: vc/bzr.py
===================================================================
--- vc/bzr.py	(revision 1326)
+++ vc/bzr.py	(working copy)
@@ -36,7 +36,7 @@
 
     def __init__(self, location):
         self._tree_cache = None
-        _vc.Vc.__init__(self, location)
+        super(Vc, self).__init__(location)
 
     def commit_command(self, message):
         return [self.CMD,"commit","-m",message]
Index: vc/monotone.py
===================================================================
--- vc/monotone.py	(revision 1326)
+++ vc/monotone.py	(working copy)
@@ -27,29 +27,29 @@
 import errno
 
 class Vc(_vc.Vc):
-    CMD = "mtn"
     NAME = "Monotone"
     PATCH_STRIP_NUM = 0
     PATCH_INDEX_RE = "^[+]{3,3} ([^  ]*)\t[0-9a-f]{40,40}$"
 
     def __init__(self, location):
         self._tree_cache = None
-        location = os.path.normpath(location)
-
+        self.interface_version = 0.0
+        self.CMD = None
+        self.choose_monotone_version()
+        super(Vc, self).__init__(os.path.normpath(location))
+        
+    def choose_monotone_version(self):
         try:
             # for monotone >= 0.26
             self.VC_DIR = "_MTN"
-            self.root = self.find_repo_root(location)
-            self.interface_version = float(os.popen("mtn" + " automate interface_version").read())
+            self.CMD = "mtn"
+            self.interface_version = float(os.popen(self.CMD + " automate interface_version").read())
             if self.interface_version > 9.0:
                 print "WARNING: Unsupported interface version (please report any problems to the meld mailing list)"
-            return
         except ValueError:
-            # for monotone <= 0.25 (different metadata directory, different executable)
+            # for monotone <= 0.25
             self.VC_DIR = "MT"
             self.CMD = "monotone"
-            self.root = self.find_repo_root(location)
-            return
 
     def commit_command(self, message):
         return [self.CMD,"commit","-m",message]
Index: vc/svn.py
===================================================================
--- vc/svn.py	(revision 1326)
+++ vc/svn.py	(working copy)
@@ -30,6 +30,7 @@
     CMD = "svn"
     NAME = "Subversion"
     VC_DIR = ".svn"
+    VC_ROOT_WALK = False
     PATCH_INDEX_RE = "^Index:(.*)$"
     state_map = {
                  "?": _vc.STATE_NONE,
@@ -42,11 +43,6 @@
                  "C": _vc.STATE_CONFLICT,
                  }
 
-    def __init__(self, location):
-        if not os.path.isdir(os.path.join(location, self.VC_DIR)):
-            raise ValueError()
-        self.root = location
-
     def commit_command(self, message):
         return [self.CMD,"commit","-m",message]
     def diff_command(self):
Index: vc/_vc.py
===================================================================
--- vc/_vc.py	(revision 1326)
+++ vc/_vc.py	(working copy)
@@ -71,9 +71,13 @@
     PATCH_STRIP_NUM = 0
     PATCH_INDEX_RE = ''
     VC_DIR = None
+    VC_ROOT_WALK = True
 
     def __init__(self, location):
-        self.root = self.find_repo_root(location)
+        if self.VC_ROOT_WALK:
+            self.root = self.find_repo_root(location)
+        else:
+            self.root = self.is_repo_root(location)
 
     def commit_command(self, message):
         raise NotImplementedError()
@@ -90,14 +94,19 @@
     def patch_command(self, workdir):
         return ["patch","--strip=%i"%self.PATCH_STRIP_NUM,"--reverse","--directory=%s" % workdir]
 
-    def find_repo_root(self, start):
+    def is_repo_root(self, location):
+        if not os.path.isdir(os.path.join(location, self.VC_DIR)):
+            raise ValueError
+        return location
+
+    def find_repo_root(self, location):
         while True:
-            if os.path.isdir(os.path.join(start, self.VC_DIR)):
-                return start
-            tmp = os.path.dirname(start)
-            if tmp == start:
+            if os.path.isdir(os.path.join(location, self.VC_DIR)):
+                return location
+            tmp = os.path.dirname(location)
+            if tmp == location:
                 break
-            start = tmp
+            location = tmp
         raise ValueError()
 
     def get_working_directory(self, workdir):
Index: vc/tla.py
===================================================================
--- vc/tla.py	(revision 1326)
+++ vc/tla.py	(working copy)
@@ -67,7 +67,7 @@
 
     def __init__(self, location):
         self._cached_statuses = None
-        _vc.Vc.__init__(self, location)
+        super(Vc, self).__init__(location)
 
     def commit_command(self, message):
         return [self.CMD, "commit",
Index: vc/git.py
===================================================================
--- vc/git.py	(revision 1326)
+++ vc/git.py	(working copy)
@@ -42,7 +42,7 @@
     def __init__(self, location):
         self._tree_cache = None
         try:
-            _vc.Vc.__init__(self, location)
+            super(Vc, self).__init__(location)
         except ValueError:
             gitdir = os.environ.get("GIT_DIR")
             if gitdir and os.path.isdir(gitdir):
Index: vc/rcs.py
===================================================================
--- vc/rcs.py	(revision 1326)
+++ vc/rcs.py	(working copy)
@@ -29,14 +29,10 @@
     CMD = "rcs"
     NAME = "RCS"
     VC_DIR = "RCS"
+    VC_ROOT_WALK = False
     PATCH_STRIP_NUM = 0
     PATCH_INDEX_RE = "^[+]{3} ([^\t]*)\t.*$"
 
-    def __init__(self, location):
-        if not os.path.isdir(os.path.join(location, self.VC_DIR)):
-            raise ValueError
-        self.root = location
-
     def commit_command(self, message):
         return ["ci", "-l", "-m", message]