gpg4libre: We want to use C++ library instead

in particular, the one from gpgme project. configure check is set
up in such a way that it will fail with older gpgmepp that depends
on KDE development packages.

This means Linux distros released before 2016 have to rely upon
in-tree version, but such is life ...

Change-Id: I5cdceffad6e81643603fcdee57a7656218f76834
Reviewed-on: https://gerrit.libreoffice.org/34130
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Siegmund Gorr <siegmund.gorr@cib.de>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

3 files changed, 22 insertions, 23 deletions

diff --git a/RepositoryExternal.mk b/RepositoryExternal.mk
index da85d052ffd5..48c687267a3e 100644
--- a/RepositoryExternal.mk
+++ b/RepositoryExternal.mk
@@ -3391,7 +3391,7 @@ endef
 
 endif # ENABLE_BREAKPAD
 
-ifneq ($(SYSTEM_GPGME),)
+ifneq ($(SYSTEM_GPGMEPP),)
 
 gb_ExternalProject__use_gpgme:=
 gb_ExternalProject__use_libassuan:=
@@ -3400,11 +3400,11 @@ gb_ExternalProject__use_libgpg-error:=
 define gb_LinkTarget__use_gpgme
 $(call gb_LinkTarget_set_include,$(1),\
 	$$(INCLUDE) \
-	$$(GPGME_CFLAGS) \
+	$$(GPGMEPP_CFLAGS) \
 )
 
 $(call gb_LinkTarget_add_libs,$(1),\
-    $(GPGME_LIBS) \
+    $(GPGMEPP_LIBS) \
 )
 
 endef
diff --git a/config_host.mk.in b/config_host.mk.in
index 1dfca596b5cf..5c35440ed0ad 100644
--- a/config_host.mk.in
+++ b/config_host.mk.in
@@ -204,8 +204,8 @@ export EPOXY_LIBS=$(gb_SPACE)@EPOXY_LIBS@
 export GLM_CFLAGS=$(gb_SPACE)@GLM_CFLAGS@
 export GPG_ERROR_CFLAGS=$(gb_SPACE)@GPG_ERROR_CFLAGS@
 export GPG_ERROR_LIBS=$(gb_SPACE)@GPG_ERROR_LIBS@
-export GPGME_CFLAGS=$(gb_SPACE)@GPGME_CFLAGS@
-export GPGME_LIBS=$(gb_SPACE)@GPGME_LIBS@
+export GPGMEPP_CFLAGS=$(gb_SPACE)@GPGMEPP_CFLAGS@
+export GPGMEPP_LIBS=$(gb_SPACE)@GPGMEPP_LIBS@
 export GNUTLS_CFLAGS=$(gb_SPACE)@GNUTLS_CFLAGS@
 export GNUTLS_LIBS=$(gb_SPACE)@GNUTLS_LIBS@
 export PARALLELISM?=@PARALLELISM@
@@ -510,7 +510,7 @@ export SYSTEM_GENCCODE=@SYSTEM_GENCCODE@
 export SYSTEM_GENCMN=@SYSTEM_GENCMN@
 export SYSTEM_EPOXY=@SYSTEM_EPOXY@
 export SYSTEM_GLM=@SYSTEM_GLM@
-export SYSTEM_GPGME=@SYSTEM_GPGME@
+export SYSTEM_GPGMEPP=@SYSTEM_GPGMEPP@
 export SYSTEM_GRAPHITE=@SYSTEM_GRAPHITE@
 export SYSTEM_HARFBUZZ=@SYSTEM_HARFBUZZ@
 export SYSTEM_HSQLDB=@SYSTEM_HSQLDB@
diff --git a/configure.ac b/configure.ac
index df4b75c84728..d7532cbb9e3d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1759,10 +1759,10 @@ AC_ARG_WITH(system-poppler,
         [Use system poppler (only needed for PDF import).]),,
     [with_system_poppler="$with_system_libs"])
 
-AC_ARG_WITH(system-gpgme,
-    AS_HELP_STRING([--with-system-gpgme],
+AC_ARG_WITH(system-gpgmepp,
+    AS_HELP_STRING([--with-system-gpgmepp],
         [Use gpgme already on system]),,
-    [with_system_gpgme="$with_system_libs"])
+    [with_system_gpgmepp="$with_system_libs"])
 
 AC_ARG_WITH(system-apache-commons,
     AS_HELP_STRING([--with-system-apache-commons],
@@ -10444,25 +10444,24 @@ else
 fi
 AC_SUBST(ENABLE_PDFIUM)
 
-SYSTEM_GPGME=
+SYSTEM_GPGMEPP=
 if test "$_os" = "Linux"; then
     dnl ===================================================================
     dnl Check for system gpgme
     dnl ===================================================================
-    AC_MSG_CHECKING([which gpgme to use])
-    if test "$with_system_gpgme" = "yes"; then
+    AC_MSG_CHECKING([which gpgmepp to use])
+    if test "$with_system_gpgmepp" = "yes"; then
         AC_MSG_RESULT([external])
-        SYSTEM_GPGME=TRUE
+        SYSTEM_GPGMEPP=TRUE
 
-        AC_PATH_PROG(GPGMECONFIG, gpgme-config)
-        if test -z "$GPGMECONFIG"; then
-            AC_MSG_ERROR([--with-system-gpgme requested, but gpgme programs not found])
-        fi
-
-        GPGME_CFLAGS=`$GPGMECONFIG --cflags`
-        GPGME_LIBS=`$GPGMECONFIG --libs`
+        # C++ library doesn't come with fancy gpgmepp-config, check for headers the old-fashioned way
+        AC_CHECK_HEADER(gpgme++/gpgmepp_version.h, [ GPGMEPP_CFLAGS=-I/usr/include/gpgme++ ],
+            [AC_MSG_ERROR(gpgmepp headers not found, install gpgmepp development package)], [])
+        # progress_callback is the only func with plain C linkage
+        # checking for it also filters out older, KDE-dependent libgpgmepp versions
+        AC_CHECK_LIB(gpgmepp, progress_callback, [ GPGMEPP_LIBS=-lgpgmepp ],
+            [AC_MSG_ERROR(gpgmepp not found or not functional)], [])
     else
-# This is work in progress, please DO NOT MODIFY OR REMOVE
         AC_MSG_RESULT([internal])
         BUILD_TYPE="$BUILD_TYPE LIBGPGERROR LIBASSUAN GPGME"
 
@@ -10477,8 +10476,8 @@ AC_SUBST(GPG_ERROR_CFLAGS)
 AC_SUBST(GPG_ERROR_LIBS)
 AC_SUBST(LIBASSUAN_CFLAGS)
 AC_SUBST(LIBASSUAN_LIBS)
-AC_SUBST(GPGME_CFLAGS)
-AC_SUBST(GPGME_LIBS)
+AC_SUBST(GPGMEPP_CFLAGS)
+AC_SUBST(GPGMEPP_LIBS)
 
 AC_MSG_CHECKING([whether to build the Wiki Publisher extension])
 if test "x$enable_ext_wiki_publisher" = "xyes" -a "x$enable_extension_integration" != "xno" -a "$with_java" != "no"; then