kde-apps/okular: Fix musl build (implicit vasprintf decl)

KDE-Bug: https://bugs.kde.org/show_bug.cgi?id=398338
Upstream MR: https://invent.kde.org/graphics/okular/-/merge_requests/722

Cherry-picked from upstream's upstream:
4b0590e7d1

Closes: https://bugs.gentoo.org/922345
Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>

kde-apps/okular/files/okular-23.08.5-implicit-vasprintf.patch

@@ -0,0 +1,29 @@
+From a0f57bf7f984289c5b0ceefa2a784f97cd58428a Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Germ=C3=A1n=20Poo-Caama=C3=B1o?= <gpoo@gnome.org>
+Date: Sat, 30 May 2020 16:15:27 -0400
+Subject: [PATCH] Fix implicit declaration of vasprintf
+
+Fix build when compiling with `-Werror=implicit-function-declaration`.
+---
+ core/synctex/synctex_parser.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/core/synctex/synctex_parser.c b/core/synctex/synctex_parser.c
+index 9eed566b3..a67006d39 100644
+--- a/core/synctex/synctex_parser.c
++++ b/core/synctex/synctex_parser.c
+@@ -55,6 +55,11 @@
+  *  First level objects are sheets and forms, containing boxes, glues, kerns...
+  *  The third tree allows to browse leaves according to tag and line.
+  */
++/* Declare _GNU_SOURCE for accessing vasprintf. For MSC compiler, vasprintf is
++ * defined in this file
++ */
++#define _GNU_SOURCE
++
+ #if defined(SYNCTEX_USE_LOCAL_HEADER)
+ #include "synctex_parser_local.h"
+ #else
+-- 
+2.44.0
+

kde-apps/okular/okular-23.08.5.ebuild

@@ -72,6 +72,7 @@ RDEPEND="${DEPEND}
 PATCHES=(
 	"${FILESDIR}/${PN}-21.11.80-tests.patch" # bug 734138
 	"${FILESDIR}/${PN}-20.08.2-hide-mobile-app.patch" # avoid same-name entry
+	"${FILESDIR}/${P}-implicit-vasprintf.patch" # bug 922345; pending upstream
 )
 
 src_configure() {

kde-apps/okular/okular-24.02.2.ebuild

@@ -66,6 +66,7 @@ RDEPEND="${DEPEND}
 PATCHES=(
 	"${FILESDIR}/${PN}-24.01.80-tests.patch" # bug 734138
 	"${FILESDIR}/${PN}-20.08.2-hide-mobile-app.patch" # avoid same-name entry
+	"${FILESDIR}/${PN}-23.08.5-implicit-vasprintf.patch" # bug 922345; pending upstream
 )
 
 src_configure() {