From 047be3e733cff7717ccd49d6422ea0002bd0c515 Mon Sep 17 00:00:00 2001
From: Jan Synacek <jsynacek@redhat.com>
Date: Mon, 16 Jan 2017 13:00:03 +0100
Subject: [PATCH] build-sys: check for lz4 in the old and new numbering scheme
 (#4717)

lz4 upstream decided to switch to an incompatible numbering scheme
(1.7.3 follows 131, to match the so version).  PKG_CHECK_MODULES does
not allow two version matches for the same package, so e.g. lz4 < 10 ||
lz4 >= 125 cannot be used. Check twice, once for "new" numbers (anything
below 10 is assume to be new), once for the "old" numbers (anything
above >= 125). This assumes that the "new" versioning will not get to 10
to quickly. I think that's a safe assumption, lz4 is a mature project.

Fixed #4690.

Cherry-picked from
https://github.com/systemd/systemd/commit/3d4cf7de48a74726694abbaa09f9804b845ff3ba

Resolves: #1404406
---
 configure.ac | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index cf595e6..4a0b269 100644
--- a/configure.ac
+++ b/configure.ac
@@ -602,10 +602,13 @@ AM_CONDITIONAL(HAVE_BZIP2, [test "$have_bzip2" = "yes"])
 have_lz4=no
 AC_ARG_ENABLE(lz4, AS_HELP_STRING([--disable-lz4], [Disable optional LZ4 support]))
 AS_IF([test "x$enable_lz4" != "xno"], [
-        PKG_CHECK_MODULES(LZ4, [ liblz4 >= 125 ],
-               [AC_DEFINE(HAVE_LZ4, 1, [Define in LZ4 is available])
+        PKG_CHECK_MODULES(LZ4, [ liblz4 < 10 ],
+               [AC_DEFINE(HAVE_LZ4, 1, [Define if LZ4 is available])
                 have_lz4=yes],
-                have_lz4=no)
+                [PKG_CHECK_MODULES(LZ4, [ liblz4 >= 125 ],
+                      [AC_DEFINE(HAVE_LZ4, 1, [Define if LZ4 is available])
+                      have_lz4=yes],
+                      have_lz4=no)])
         AS_IF([test "x$have_lz4" = xno -a "x$enable_lz4" = xyes],
               [AC_MSG_ERROR([*** LZ4 support requested but libraries not found])])
 ])
-- 
2.9.3