Guard a few Makefile variables against user environments
Some variables are not initialized in the Makefile, but appended to. If
the user has those variables in her environment, it will break the
build.
The variable names were found using these commands:
$ s='[ \t]';
$ S='[^ \t]';
$ comm -23 \
<(sed -n "s/^$s*\($S*\)$s$s*+=.*/\1/p" < Makefile |
sort | uniq) \
<(sed -n "s/^$s*\($S*\)$s$s*=.*/\1/p" < Makefile |
sort | uniq)
This fixes msysGit issue 216.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>