Explain that git switches to the root before running any command

diff --git a/pep-103.txt b/pep-103.txt
index 07831041b88393f091a25f68abfbba7372f3c348..f6e8e6d4d8d7d8e780910de4e0f189a37d65b753 100644 (file)
--- a/pep-103.txt
+++ b/pep-103.txt
@@ -753,6 +753,34 @@ See `WhatIsTheIndex
 Wiki.
 
 
+Root
+====
+
+Git switches to the root (top-level directory of the project where
+``.git`` subdirectory exists) before running any command. Git
+remembers though the directory that was current before the switch.
+Some programs take into account the current directory. E.g., ``git
+status`` shows file paths of changed and unknown files relative to the
+current directory; ``git grep`` searches below the current directory;
+``git apply`` applies only those hunks from the patch that touch files
+below the current directory.
+
+But most commands run from the root and ignore the current directory.
+Imagine, for example, that you have two work trees, one for the branch
+``v1`` and the other for ``master``. If you want to merge ``v1`` from
+a subdirectory inside the second work tree you must write commands as
+if you're in the top-level dir. Let take two work trees,
+``project-v1`` and ``project``, for example::
+
+    $ cd project/subdirectory
+    $ git fetch ../project-v1 v1:v1
+    $ git merge v1
+
+Please note the path in ``git fetch ../project-v1 v1:v1`` is
+``../project-v1`` and not ``../../project-v1`` despite the fact that
+we run the commands from a subdirectory, not from the root.
+
+
 ReReRe
 ======