Adding patch to avoid overriding build-environment.

Signed-off-by: Daniel Baumann <daniel@debian.org>

debian/patches/debian/0001-build.patch

@@ -0,0 +1,21 @@
+Author: Daniel Baumann <daniel.baumann@progress-linux.org>
+Description: Avoid overwriting build-environment.
+
+diff -Naurp xlunzip.orig/configure xlunzip/configure
+--- xlunzip.orig/configure
++++ xlunzip/configure
+@@ -20,10 +20,10 @@ bindir='$(exec_prefix)/bin'
+ datarootdir='$(prefix)/share'
+ infodir='$(datarootdir)/info'
+ mandir='$(datarootdir)/man'
+-CC=gcc
+-CPPFLAGS=
+-CFLAGS='-Wall -W -O2'
+-LDFLAGS=
++#CC=gcc
++#CPPFLAGS=
++#CFLAGS='-Wall -W -O2'
++#LDFLAGS=
+ MAKEINFO=makeinfo
+ 
+ # checking whether we are using GNU C.

debian/patches/series

@@ -0,0 +1 @@
+debian/0001-build.patch