build shared library with correct compiler flags

* lib-make.patch: Fix regression in 1.4.5 lib/Makefile
* zstd.spec: Apply the patch

lib-make.patch

@@ -0,0 +1,38 @@
+From 66db79bbb0977bea7023000dca6211c2cacf9a07 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
+Date: Mon, 25 May 2020 13:16:31 +0100
+Subject: [PATCH] fix generalization of pattern rules in lib/Makefile
+
+This was introduced in v1.4.4-383-gf77fd5ce
+and results in the default rule in lib/ doing nothing.
+---
+ lib/Makefile | 10 +++++-----
+ 1 file changed, 5 insertions(+), 5 deletions(-)
+
+diff --git a/lib/Makefile b/lib/Makefile
+index e6213ac8..de437a98 100644
+--- a/lib/Makefile
++++ b/lib/Makefile
+@@ -221,14 +221,14 @@ libzstd : $(LIBZSTD)
+ lib : libzstd.a libzstd
+ 
+ .PHONY: lib-mt
+-%-mt : CPPFLAGS += -DZSTD_MULTITHREAD
+-%-mt : LDFLAGS  += -pthread
+-%-mt : %
++% : CPPFLAGS += -DZSTD_MULTITHREAD
++% : LDFLAGS  += -pthread
++% : lib
+ 	@echo multi-threading build completed
+ 
+ .PHONY: lib-release
+-%-release : DEBUGFLAGS :=
+-%-release : %
++% : DEBUGFLAGS :=
++% : lib
+ 	@echo release build completed
+ 
+ 
+-- 
+2.26.2
+

zstd.spec

@@ -13,7 +13,7 @@
 
 Name:           zstd
 Version:        1.4.5
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        Zstd compression library
 
 License:        BSD and GPLv2
@@ -21,6 +21,7 @@ URL:            https://github.com/facebook/zstd
 Source0:        https://github.com/facebook/zstd/archive/v%{version}.tar.gz#/%{name}-%{version}.tar.gz
 
 Patch1:         pzstd.1.patch
+Patch2:         lib-make.patch
 
 BuildRequires:  gcc gtest-devel
 %if %{with pzstd}
@@ -57,6 +58,7 @@ find -name .gitignore -delete
 %if %{with pzstd}
 %patch1 -p1
 %endif
+%patch2 -p1
 
 %build
 export CFLAGS="$RPM_OPT_FLAGS"
@@ -122,6 +124,9 @@ install -D -m644 programs/%{name}.1 %{buildroot}%{_mandir}/man1/p%{name}.1
 %ldconfig_scriptlets -n lib%{name}
 
 %changelog
+* Fri May 25 2020 Pádraig Brady <P@draigBrady.com> - 1.4.5-2
+- Build shared library with correct compiler flags
+
 * Fri May 22 2020 Pádraig Brady <P@draigBrady.com> - 1.4.5-1
 - Latest upstream