sci-chemistry/elem: fix build with gcc-10

Closes: https://github.com/gentoo/gentoo/pull/18431
Closes: https://bugs.gentoo.org/706938
Package-Manager: Portage-3.0.9, Repoman-3.0.1
Signed-off-by: Jakov Smolic <jakov.smolic@sartura.hr>
Signed-off-by: David Seifert <soap@gentoo.org>

sci-chemistry/elem/elem-1.0.3-r2.ebuild

@@ -12,7 +12,6 @@ SRC_URI="mirror://sourceforge/elem/${PN}-src-${PV}-Linux.tgz"
 LICENSE="GPL-2"
 KEYWORDS="amd64 sparc x86"
 SLOT="0"
-IUSE=""
 
 DEPEND="x11-libs/xforms"
 RDEPEND="${DEPEND}"
@@ -20,6 +19,7 @@ RDEPEND="${DEPEND}"
 PATCHES=(
 	"${FILESDIR}"/${P}-fix-build-system.patch
 	"${FILESDIR}"/${P}-missing-stdlib.patch
+	"${FILESDIR}"/${P}-fno-common.patch
 )
 
 src_configure() {

sci-chemistry/elem/files/elem-1.0.3-fno-common.patch

@@ -0,0 +1,24 @@
+--- a/elem.c
++++ b/elem.c
+@@ -11,6 +11,9 @@
+ #include "deutsch.h"
+ #endif
+ 
++double amsumme;
++FL_OBJECT *massensumme;
++
+ 
+ 
+ FD_Periodensystem *create_form_Periodensystem(void)
+--- a/elem.h
++++ b/elem.h
+@@ -154,7 +154,7 @@ typedef struct {
+   void *vdata;
+   long ldata;
+ } FD_Periodensystem;
+-double amsumme;
++extern double amsumme;
+ extern FD_Periodensystem * create_form_Periodensystem(void);
+-        FL_OBJECT *massensumme;
++extern FL_OBJECT *massensumme;
+ #endif /* FD_Periodensystem_h_ */