[freetype2] master 2b672e721: * builds/unix/configure.raw: Restore `SYSTEM_ZLIB` variable.

[Werner Lemberg]

branch: master
commit 2b672e7210a6e989aca4787fb81f4b2542bad9c1
Author: Werner Lemberg <wl@gnu.org>
Commit: Werner Lemberg <wl@gnu.org>

    * builds/unix/configure.raw: Restore `SYSTEM_ZLIB` variable.
    
    This was accidentally removed with commit 93ebcbd0 almost eight years ago.
---
 builds/unix/configure.raw          | 6 ++++++
 devel/ftoption.h                   | 4 ++++
 include/freetype/config/ftoption.h | 4 ++++
 3 files changed, 14 insertions(+)

diff --git a/builds/unix/configure.raw b/builds/unix/configure.raw
index f326872cb..c5221dab9 100644
--- a/builds/unix/configure.raw
+++ b/builds/unix/configure.raw
@@ -317,6 +317,12 @@ if test x"$with_zlib" = xyes -a "$have_zlib" = no; then
   AC_MSG_ERROR([external zlib support requested but library not found])
 fi
 
+SYSTEM_ZLIB=
+if test "$have_zlib" != no; then
+  SYSTEM_ZLIB=yes
+fi
+AC_SUBST([SYSTEM_ZLIB])
+
 
 # check for system libbz2
 
diff --git a/devel/ftoption.h b/devel/ftoption.h
index f92b4167a..a99c4c97d 100644
--- a/devel/ftoption.h
+++ b/devel/ftoption.h
@@ -219,6 +219,10 @@ FT_BEGIN_HEADER
    *   If you use a build system like cmake or the `configure` script,
    *   options set by those programs have precedence, overwriting the value
    *   here with the configured one.
+   *
+   *   If you use the GNU make build system directly (that is, without the
+   *   `configure` script) and you define this macro, you also have to pass
+   *   `SYSTEM_ZLIB=yes` as an argument to make.
    */
 /* #define FT_CONFIG_OPTION_SYSTEM_ZLIB */
 
diff --git a/include/freetype/config/ftoption.h 
b/include/freetype/config/ftoption.h
index 4227fd376..487b33364 100644
--- a/include/freetype/config/ftoption.h
+++ b/include/freetype/config/ftoption.h
@@ -219,6 +219,10 @@ FT_BEGIN_HEADER
    *   If you use a build system like cmake or the `configure` script,
    *   options set by those programs have precedence, overwriting the value
    *   here with the configured one.
+   *
+   *   If you use the GNU make build system directly (that is, without the
+   *   `configure` script) and you define this macro, you also have to pass
+   *   `SYSTEM_ZLIB=yes` as an argument to make.
    */
 /* #define FT_CONFIG_OPTION_SYSTEM_ZLIB */