add possibility to select specific jdk with env var; rel 2

proposed in:
mesonbuild/meson#14951

but suffers from:
mesonbuild/meson#14953

so needs to be used carefully

Author: jpalus

javac-selection.patch

@@ -0,0 +1,28 @@
+From 04cd0e2e0057146782df0085995408856ceff5d0 Mon Sep 17 00:00:00 2001
+From: Jan Palus <[email protected]>
+Date: Mon, 25 Aug 2025 14:10:37 +0200
+Subject: [PATCH] Allow explicit selection of Java compiler
+
+Makes Java more consistent with other compilers and allows explicit
+selection of Java compiler version and/or provider when building with
+Meson.
+---
+ docs/markdown/Reference-tables.md | 1 +
+ mesonbuild/envconfig.py           | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/mesonbuild/envconfig.py b/mesonbuild/envconfig.py
+index 43fad0cd2..c85d8da90 100644
+--- a/mesonbuild/envconfig.py
++++ b/mesonbuild/envconfig.py
+@@ -101,6 +101,7 @@ ENV_VAR_COMPILER_MAP: T.Mapping[str, str] = {
+     'rust': 'RUSTC',
+     'vala': 'VALAC',
+     'nasm': 'NASM',
++    'java': 'JAVAC',
+ 
+     # Linkers
+     'c_ld': 'CC_LD',
+-- 
+2.51.0
+

meson.spec

@@ -2,7 +2,7 @@ Summary:	High productivity build system
 Summary(pl.UTF-8):	System budowania o dużej produktywności
 Name:		meson
 Version:	1.8.1
-Release:	1
+Release:	2
 License:	Apache v2.0
 Group:		Development/Tools
 #Source0Download: https://github.com/mesonbuild/meson/releases/
@@ -12,6 +12,7 @@ Patch0:		%{name}-gtkdocdir.patch
 Patch1:		rust-proc-macro-filter-out-target.patch
 Patch2:		allow-arm-on-arm64.patch
 Patch3:		rpm-macros-pld.patch
+Patch4:		javac-selection.patch
 URL:		https://mesonbuild.com/
 BuildRequires:	ninja >= 1.8.2
 BuildRequires:	python3 >= 1:3.7
@@ -59,6 +60,7 @@ Mesona.
 %patch -P1 -p1
 %patch -P2 -p1 -R
 %patch -P3 -p1
+%patch -P4 -p1
 
 %{__sed} -i -e '1s,/usr/bin/env python3,%{__python3},' \
 	meson.py