[PATCH] add option to find zlib in custom path

[Robert Schiele <rschiele@gmail.com>]

Some systems do not provide zlib development headers and libraries in
default search path of the compiler.  For these systems we should allow
specifying the location by --with-zlib=PATH or by setting ZLIB_PATH in
the makefile.

Signed-off-by: Robert Schiele <rschiele@gmail.com>
---

You can also fetch this patch as d669d5f17feb3b406862fd83b42998b2353da44f from
git://schiele.dyndns.org/git

 Makefile     |    8 +++++++-
 configure.ac |    3 +++
 2 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 73b487f..21bf5c7 100644
--- a/Makefile
+++ b/Makefile
@@ -372,7 +372,7 @@ BUILTIN_OBJS = \
 	builtin-pack-refs.o
 
 GITLIBS = $(LIB_FILE) $(XDIFF_LIB)
-EXTLIBS = -lz
+EXTLIBS =
 
 #
 # Platform specific tweaks
@@ -517,6 +517,12 @@ ifndef NO_CURL
 	endif
 endif
 
+ifdef ZLIB_PATH
+	BASIC_CFLAGS += -I$(ZLIB_PATH)/include
+	EXTLIBS += -L$(ZLIB_PATH)/lib $(CC_LD_DYNPATH)$(ZLIB_PATH)/lib
+endif
+EXTLIBS += -lz
+
 ifndef NO_OPENSSL
 	OPENSSL_LIBSSL = -lssl
 	ifdef OPENSSLDIR
diff --git a/configure.ac b/configure.ac
index 50d2b85..b2f1965 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,6 +75,9 @@ GIT_ARG_SET_PATH(shell)
 # Define PERL_PATH to provide path to Perl.
 GIT_ARG_SET_PATH(perl)
 #
+# Define ZLIB_PATH to provide path to zlib.
+GIT_ARG_SET_PATH(zlib)
+#
 # Declare the with-tcltk/without-tcltk options.
 AC_ARG_WITH(tcltk,
 AS_HELP_STRING([--with-tcltk],[use Tcl/Tk GUI (default is YES)])
-- 
1.5.2.3