dev-debug/cgdb: fix modern C issue in configure

No need for a revbump here as it failed to compile if the check failed, not
misdetecting anything.

Closes: https://bugs.gentoo.org/830222
Signed-off-by: Sam James <sam@gentoo.org>

dev-debug/cgdb/cgdb-0.8.0.ebuild

@@ -24,23 +24,26 @@ IUSE="test"
 RESTRICT="test"
 
 DEPEND="
-	sys-libs/ncurses:0=
-	sys-libs/readline:0="
-
+	sys-libs/ncurses:=
+	sys-libs/readline:=
+"
 BDEPEND="
+	sys-devel/flex
 	test? (
 		dev-util/dejagnu
 		app-misc/dtach
-	)"
-
+	)
+"
 RDEPEND="
 	${DEPEND}
-	dev-debug/gdb"
+	dev-debug/gdb
+"
 
 DOCS=( AUTHORS ChangeLog FAQ INSTALL NEWS README.md )
 
 PATCHES=(
 	"${FILESDIR}"/${P}-ar.patch
+	"${FILESDIR}"/${PN}-0.8.0-configure-c99.patch
 )
 
 src_prepare() {
@@ -48,6 +51,11 @@ src_prepare() {
 	AT_M4DIR="config" eautoreconf
 }
 
+multilib_src_configure() {
+	unset LEX
+	ECONF_SOURCE="${S}" econf
+}
+
 multilib_src_test() {
 	# Tests need an interactive shell, #654986
 
@@ -63,7 +71,3 @@ multilib_src_test() {
 	[[ -f ${T}/dtach-test.out ]] || die "Unable to run tests"
 	[[ $(<"${T}"/dtach-test.out) == 0 ]] || die "Tests failed"
 }
-
-multilib_src_configure() {
-	ECONF_SOURCE="${S}" econf
-}

dev-debug/cgdb/files/cgdb-0.8.0-configure-c99.patch

@@ -0,0 +1,23 @@
+https://bugs.gentoo.org/830222
+https://github.com/cgdb/cgdb/pull/338
+
+From 039dba0ec3ae2c4b2636418652a5c63f9ff86049 Mon Sep 17 00:00:00 2001
+From: Florian Weimer <fweimer@redhat.com>
+Date: Wed, 8 Mar 2023 11:29:06 +0100
+Subject: [PATCH] configure: Avoid implicit int in readline check
+
+Future compilers will not accept implicit ints by default, altering
+the outcome of the check without this change.
+
+Signed-off-by: Florian Weimer <fweimer@redhat.com>
+--- a/config/readline_check_version.m4
++++ b/config/readline_check_version.m4
+@@ -86,7 +86,7 @@ AC_CACHE_VAL(ac_cv_rl_version,
+ #include <stdlib.h>
+ #include <readline/readline.h>
+ 
+-main()
++int main(void)
+ {
+ 	FILE *fp;
+ 	fp = fopen("conftest.rlv", "w");