build: use patch rather than sed in zeromq package

Author: fanquake

depends/packages/zeromq.mk

@@ -3,6 +3,7 @@ $(package)_version=4.3.1
 $(package)_download_path=https://github.com/zeromq/libzmq/releases/download/v$($(package)_version)/
 $(package)_file_name=$(package)-$($(package)_version).tar.gz
 $(package)_sha256_hash=bcbabe1e2c7d0eec4ed612e10b94b112dd5f06fcefa994a0c79a45d835cd21eb
+$(package)_patches=remove_libstd_link.patch
 
 define $(package)_set_vars
   $(package)_config_opts=--without-docs --disable-shared --disable-curve --disable-curve-keygen --disable-perf
@@ -15,7 +16,8 @@ define $(package)_set_vars
 endef
 
 define $(package)_preprocess_cmds
-   cp -f $(BASEDIR)/config.guess $(BASEDIR)/config.sub config
+  patch -p1 < $($(package)_patch_dir)/remove_libstd_link.patch && \
+  cp -f $(BASEDIR)/config.guess $(BASEDIR)/config.sub config
 endef
 
 define $(package)_config_cmds
@@ -31,6 +33,5 @@ define $(package)_stage_cmds
 endef
 
 define $(package)_postprocess_cmds
-  sed -i.old "s/ -lstdc++//" lib/pkgconfig/libzmq.pc && \
   rm -rf bin share lib/*.la
 endef

depends/patches/zeromq/remove_libstd_link.patch

@@ -0,0 +1,25 @@
+commit 47d4cd12a2c051815ddda78adebdb3923b260d8a
+Author: fanquake <[email protected]>
+Date:   Tue Aug 18 14:45:40 2020 +0800
+
+    Remove needless linking against libstdc++
+
+    This is broken for a number of reasons, including:
+    - g++ understands "static-libstdc++ -lstdc++" to mean "link against
+      whatever libstdc++ exists, probably shared", which in itself is buggy.
+    - another stdlib (libc++ for example) may be in use
+
+    See #11981.
+
+diff --git a/src/libzmq.pc.in b/src/libzmq.pc.in
+index 233bc3a..3c2bf0d 100644
+--- a/src/libzmq.pc.in
++++ b/src/libzmq.pc.in
+@@ -7,6 +7,6 @@ Name: libzmq
+ Description: 0MQ c++ library
+ Version: @VERSION@
+ Libs: -L${libdir} -lzmq
+-Libs.private: -lstdc++ @pkg_config_libs_private@
++Libs.private: @pkg_config_libs_private@
+ Requires.private: @pkg_config_names_private@
+ Cflags: -I${includedir} @pkg_config_defines@