[PATCH v2] Makefile: Simplify handling of python scripts

[Brian Gernhardt <brian@gernhardtsoftware.com>]

The sed script intended to add a standard opening to python scripts
was non-compatible and overly complex.  Simplifying it down to a set
of one-liners removes the compatibility issues of newlines.  Moving
the environment alterations from the Makefile to the python scripts
makes also makes the scripts easier to run in-place.

Specifically, the new sed script:

 - Alters the shebang line to use the configured Python.
 - Alters any os.getenv("GITPYTHONLIB") calls to use @@INSTLIBDIR@@ as the
   default.  This will replace any existing default or add a default if
   none is provided.
 - Replaces the @@INSTLIBDIR@@ placeholder with the directory git installs
   its python libraries to.

The last two steps could be combined into a single step, but is left
separate in case someone has another need for @@INSTLIBDIR@@ in their
script.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Brian Gernhardt <brian@gernhardtsoftware.com>
---

  On Apr 9, 2010, at 11:39 AM, Sverre Rabbelier wrote:

  > My sed foo is not that great, can you explain (in the commit message)
  > what exactly the new sed script does?
  
  Certainly.  (And the commit message is the only change from v1.)

 Makefile              |    9 ++-------
 git-remote-testgit.py |    2 ++
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index f0fe351..87c90d6 100644
--- a/Makefile
+++ b/Makefile
@@ -1629,13 +1629,8 @@ $(patsubst %.py,%,$(SCRIPT_PYTHON)): % : %.py
 	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C git_remote_helpers -s \
 		--no-print-directory prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' \
 		instlibdir` && \
-	sed -e '1{' \
-	    -e '	s|#!.*python|#!$(PYTHON_PATH_SQ)|' \
-	    -e '}' \
-	    -e 's|^import sys.*|&; \\\
-	           import os; \\\
-	           sys.path.insert(0, os.getenv("GITPYTHONLIB",\
-	                                        "@@INSTLIBDIR@@"));|' \
+	sed -e '1s|#!.*python|#!$(PYTHON_PATH_SQ)|' \
+	    -e 's|\(os\.getenv("GITPYTHONLIB"\)[^)]*)|\1,"@@INSTLIBDIR@@")|' \
 	    -e 's|@@INSTLIBDIR@@|'"$$INSTLIBDIR"'|g' \
 	    $@.py >$@+ && \
 	chmod +x $@+ && \
diff --git a/git-remote-testgit.py b/git-remote-testgit.py
index f61624e..9253922 100644
--- a/git-remote-testgit.py
+++ b/git-remote-testgit.py
@@ -2,6 +2,8 @@
 
 import hashlib
 import sys
+import os
+sys.path.insert(0, os.getenv("GITPYTHONLIB","."))
 
 from git_remote_helpers.util import die, debug, warn
 from git_remote_helpers.git.repo import GitRepo
-- 
1.7.1.rc0.243.g2ce66