Build with a private libpq

Related: #1967918
Also discussed in Fedora bug #1905584

Some extensions require to build with libpq as well, but this might be
a problem for the case server uses a private libpq, because extension
would pull in another libpq.so into the same process.

By adding new sub-packages private-libs and private-devel we can make sure
only a single copy of libpq is used by server, including the extensions.

Add dependency to libpq-devel to server-devel pkg if external libpq is used
in order to let extensions not to care about what libpq the server uses.

postgresql-no-libecpg.patch

@@ -0,0 +1,12 @@
+diff -up postgresql-13.1/src/interfaces/Makefile.patch10 postgresql-13.1/src/interfaces/Makefile
+--- postgresql-13.1/src/interfaces/Makefile.patch10	2021-02-02 21:33:23.235292305 +0100
++++ postgresql-13.1/src/interfaces/Makefile	2021-02-02 21:33:30.281365440 +0100
+@@ -12,7 +12,7 @@ subdir = src/interfaces
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ 
+-SUBDIRS = libpq ecpg
++SUBDIRS = libpq
+ 
+ $(recurse)
+ 

postgresql.spec

@@ -35,6 +35,7 @@
 # Disable temporarily to be able to build the package
 # tracked in RHBZ#1940964
 %{!?llvmjit:%global llvmjit 0}
+%{!?external_libpq:%global external_libpq 0}
 %{!?upgrade:%global upgrade 1}
 %{!?plpython3:%global plpython3 1}
 %{!?pltcl:%global pltcl 1}
@@ -109,6 +110,7 @@ Patch2: postgresql-logging.patch
 Patch5: postgresql-var-run-socket.patch
 Patch8: postgresql-external-libpq.patch
 Patch9: postgresql-server-pg_config.patch
+Patch12: postgresql-no-libecpg.patch
 
 BuildRequires: make
 BuildRequires: gcc
@@ -121,7 +123,9 @@ BuildRequires: perl-generators
 BuildRequires: readline-devel zlib-devel
 BuildRequires: systemd systemd-devel util-linux
 BuildRequires: multilib-rpm-config
+%if %external_libpq
 BuildRequires: libpq-devel >= %version
+%endif
 BuildRequires: docbook-style-xsl
 
 # postgresql-setup build requires
@@ -188,6 +192,35 @@ over a network connection.  The PostgreSQL server can be found in the
 postgresql-server sub-package.
 
 
+%if ! %external_libpq
+%package private-libs
+Summary: The shared libraries required only for this build of PostgreSQL server
+Group: Applications/Databases
+# for /sbin/ldconfig
+Requires(post): glibc
+Requires(postun): glibc
+
+%description private-libs
+The postgresql-private-libs package provides the shared libraries for this
+build of PostgreSQL server and plugins build with this version of server.
+For shared libraries used by client packages that need to connect to a
+PostgreSQL server, install libpq package instead.
+
+
+%package private-devel
+Summary: PostgreSQL development header files for this build of PostgreSQL server
+Group: Development/Libraries
+Requires: %{name}-private-libs%{?_isa} = %precise_version
+
+%description private-devel
+The postgresql-private-devel package contains the header files and libraries
+needed to compile C or C++ applications which will directly interact
+with a PostgreSQL database management server.
+You need to install this package if you want to develop applications which
+will interact with a PostgreSQL server.
+%endif
+
+
 %package server
 Summary: The programs needed to create and run a PostgreSQL server
 Requires: %{name}%{?_isa} = %precise_version
@@ -243,6 +276,14 @@ Requires: krb5-devel
 %if %llvmjit
 Requires: clang-devel llvm-devel
 %endif
+%if %external_libpq
+# Some extensions require libpq
+# Do not make them care about whether server uses private or system-wide
+# libpq, simply let the server pull the correct one
+Requires: libpq-devel
+%else
+Requires: %{name}-private-devel
+%endif
 
 %description server-devel
 The postgresql-server-devel package contains the header files and configuration
@@ -375,7 +416,11 @@ goal of accelerating analytics queries.
 %patch1 -p1
 %patch2 -p1
 %patch5 -p1
+%if %external_libpq
 %patch8 -p1
+%else
+%patch12 -p1
+%endif
 %patch9 -p1
 
 # We used to run autoconf here, but there's no longer any real need to,
@@ -383,9 +428,20 @@ goal of accelerating analytics queries.
 
 cp -p %{SOURCE1} .
 
+%if ! %external_libpq
+%global private_soname private%{majorversion}
+find . -type f -name Makefile -exec sed -i -e "s/SO_MAJOR_VERSION=\s\?\([0-9]\+\)/SO_MAJOR_VERSION= %{private_soname}-\1/" {} \;
+%endif
+
 %if %upgrade
 tar xfj %{SOURCE3}
 
+# libpq from this upgrade-only build is dropped and the libpq from the main
+# version is used. Use the same major hack therefore.
+%if ! %external_libpq
+find . -type f -name Makefile -exec sed -i -e "s/SO_MAJOR_VERSION=\s\?\([0-9]\+\)/SO_MAJOR_VERSION= %{private_soname}-\1/" {} \;
+%endif
+
 # apply once SOURCE3 is extracted
 %endif
 
@@ -616,10 +672,15 @@ make DESTDIR=$RPM_BUILD_ROOT install-world
 
 # We ship pg_config through libpq-devel
 mv $RPM_BUILD_ROOT/%_mandir/man1/pg_{,server_}config.1
+%if %external_libpq
 rm $RPM_BUILD_ROOT/%_includedir/pg_config*.h
 rm $RPM_BUILD_ROOT/%_includedir/libpq/libpq-fs.h
 rm $RPM_BUILD_ROOT/%_includedir/postgres_ext.h
 rm -r $RPM_BUILD_ROOT/%_includedir/pgsql/internal/
+%else
+ln -s pg_server_config $RPM_BUILD_ROOT/%_bindir/pg_config
+rm $RPM_BUILD_ROOT/%{_libdir}/libpq.a
+%endif
 
 # make sure these directories exist even if we suppressed all contrib modules
 install -d -m 755 $RPM_BUILD_ROOT%{_datadir}/pgsql/contrib
@@ -757,7 +818,11 @@ find_lang_bins server.lst \
 find_lang_bins contrib.lst \
 	pg_archivecleanup pg_test_fsync pg_test_timing pg_waldump
 find_lang_bins main.lst \
-	pg_dump pg_upgrade pgscripts psql
+	pg_dump pg_upgrade pgscripts psql \
+%if ! %external_libpq
+libpq%{private_soname}-5
+%endif
+
 %if %plperl
 find_lang_bins plperl.lst plperl
 %endif
@@ -830,6 +895,12 @@ make -C postgresql-setup-%{setup_version} check
 %endif
 
 
+%if ! %external_libpq
+%files private-libs
+%{_libdir}/libpq.so.*
+%endif
+
+
 %files docs
 %doc *-US.pdf
 %doc doc/html
@@ -1058,6 +1129,21 @@ make -C postgresql-setup-%{setup_version} check
 %{macrosdir}/macros.%name
 
 
+%if ! %external_libpq
+%files private-devel
+%{_bindir}/pg_config
+%{_includedir}/libpq-events.h
+%{_includedir}/libpq-fe.h
+%{_includedir}/postgres_ext.h
+%{_includedir}/pgsql/internal/*.h
+%{_includedir}/pgsql/internal/libpq/pqcomm.h
+%{_includedir}/libpq/*.h
+%{_libdir}/pkgconfig/*.pc
+%{_libdir}/libpq.so
+%{_includedir}/pg_config*.h
+%endif
+
+
 %files test-rpm-macros
 %{_datadir}/postgresql-setup/postgresql_pkg_tests.sh
 %{macrosdir}/macros.%name-test
@@ -1126,9 +1212,12 @@ make -C postgresql-setup-%{setup_version} check
 
 
 %changelog
-* Fri Jun 16 2021 Honza Horak <hhorak@redhat.com> - 13.3-1
+* Wed Jun 16 2021 Honza Horak <hhorak@redhat.com> - 13.3-1
 - Update to 13.3
   Resolves: #1964497
+- Build with a private libpq
+  Resolves: #1967918
+  (also discussed in Fedora #1905584)
 
 * Wed Jun 16 2021 Mohan Boddu <mboddu@redhat.com> - 13.2-7
 - Rebuilt for RHEL 9 BETA for openssl 3.0