Merge branches 'doc_enhancements' and 'fixes_for_mainline' into improvements_for_mainline

* doc_enhancements:
  improved repo documentation
  Improved head and tag object documentation slightly
  Added docs for the error module
  Added missing information to docstrings of commit and stats module
  improved git.cmd documentation
  Improved documentation on Actor and Blob

* fixes_for_mainline:
  repo_tests: fixed duplicate test-method name which would redefine the previous one which never ran
  Fixed Diff class which used Commits instead of Blobs - as Blobs contain the path ( in the 'name' member variable ), the a|b_path members of Diff have been removed. Tests were adjusted and run
  git.git.Git.__init__ takes None as default argument as the execute method handles this correctly
  Fixed git.blob.Blob.blame function which would return the text-per-commit as individual characters

Conflicts:
	lib/git/cmd.py
	test/git/test_repo.py

3 files changed, 43 insertions, 16 deletions

diff --git a/lib/git/blob.py b/lib/git/blob.py
index eea04490..82a41f73 100644
--- a/lib/git/blob.py
+++ b/lib/git/blob.py
@@ -152,7 +152,7 @@ class Blob(object):
                     m = re.search(r'^\t(.*)$', line)
                     text,  = m.groups()
                     blames[-1][0] = c
-                    blames[-1][1] += text
+                    blames[-1][1].append( text )
                     info = None
 
         return blames
diff --git a/lib/git/cmd.py b/lib/git/cmd.py
index 796928b3..aef53350 100644
--- a/lib/git/cmd.py
+++ b/lib/git/cmd.py
@@ -35,7 +35,7 @@ class Git(object):
 	    of the command to stdout.
 	    Set its value to 'full' to see details about the returned values.
     """
-    def __init__(self, git_dir):
+    def __init__(self, git_dir=None):
         """
         Initialize this instance with:
         
diff --git a/lib/git/diff.py b/lib/git/diff.py
index 0216e061..44f55602 100644
--- a/lib/git/diff.py
+++ b/lib/git/diff.py
@@ -5,28 +5,44 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 import re
-import commit
+import blob
 
 class Diff(object):
     """
     A Diff contains diff information between two commits.
+    
+    It contains two sides a and b of the diff, members are prefixed with 
+    "a" and "b" respectively to inidcate that.
+    
+    Diffs keep information about the changed blob objects, the file mode, renames, 
+    deletions and new files.
+    
+    There are a few cases where None has to be expected as member variable value:
+    
+    ``New File``::
+    
+        a_mode is None
+        a_blob is None
+        
+    ``Deleted File``::
+    
+        b_mode is None
+        b_blob is NOne
     """
 
-    def __init__(self, repo, a_path, b_path, a_commit, b_commit, a_mode,
+    def __init__(self, repo, a_path, b_path, a_blob, b_blob, a_mode,
                  b_mode, new_file, deleted_file, rename_from,
                  rename_to, diff):
         self.repo = repo
-        self.a_path = a_path
-        self.b_path = b_path
 
-        if not a_commit or re.search(r'^0{40}$', a_commit):
-            self.a_commit = None
+        if not a_blob or re.search(r'^0{40}$', a_blob):
+            self.a_blob = None
         else:
-            self.a_commit = commit.Commit(repo, id=a_commit)
-        if not b_commit or re.search(r'^0{40}$', b_commit):
-            self.b_commit = None
+            self.a_blob = blob.Blob(repo, id=a_blob, mode=a_mode, name=a_path)
+        if not b_blob or re.search(r'^0{40}$', b_blob):
+            self.b_blob = None
         else:
-            self.b_commit = commit.Commit(repo, id=b_commit)
+            self.b_blob = blob.Blob(repo, id=b_blob, mode=b_mode, name=b_path)
 
         self.a_mode = a_mode
         self.b_mode = b_mode
@@ -39,6 +55,17 @@ class Diff(object):
 
     @classmethod
     def list_from_string(cls, repo, text):
+        """
+        Create a new diff object from the given text
+        ``repo``
+            is the repository we are operating on - it is required 
+        
+        ``text``
+            result of 'git diff' between two commits or one commit and the index
+        
+        Returns
+            git.Diff[]
+        """
         diffs = []
 
         diff_header = re.compile(r"""
@@ -51,8 +78,8 @@ class Diff(object):
                ^new[ ]mode[ ](?P<new_mode>\d+)(?:\n|$))?
             (?:^new[ ]file[ ]mode[ ](?P<new_file_mode>.+)(?:\n|$))?
             (?:^deleted[ ]file[ ]mode[ ](?P<deleted_file_mode>.+)(?:\n|$))?
-            (?:^index[ ](?P<a_commit>[0-9A-Fa-f]+)
-                \.\.(?P<b_commit>[0-9A-Fa-f]+)[ ]?(?P<b_mode>.+)?(?:\n|$))?
+            (?:^index[ ](?P<a_blob>[0-9A-Fa-f]+)
+                \.\.(?P<b_blob>[0-9A-Fa-f]+)[ ]?(?P<b_mode>.+)?(?:\n|$))?
         """, re.VERBOSE | re.MULTILINE).match
 
         for diff in ('\n' + text).split('\ndiff --git')[1:]:
@@ -60,10 +87,10 @@ class Diff(object):
 
             a_path, b_path, similarity_index, rename_from, rename_to, \
                 old_mode, new_mode, new_file_mode, deleted_file_mode, \
-                a_commit, b_commit, b_mode = header.groups()
+                a_blob, b_blob, b_mode = header.groups()
             new_file, deleted_file = bool(new_file_mode), bool(deleted_file_mode)
 
-            diffs.append(Diff(repo, a_path, b_path, a_commit, b_commit,
+            diffs.append(Diff(repo, a_path, b_path, a_blob, b_blob,
                 old_mode or deleted_file_mode, new_mode or new_file_mode or b_mode,
                 new_file, deleted_file, rename_from, rename_to, diff[header.end():]))