patch 8.2.0290: running individual test differs from all tests

Problem:    Running individual test differs from all tests.
Solution:   Pass on environment variables. (Yee Cheng Chin, closes #5672)
diff --git a/src/testdir/Makefile b/src/testdir/Makefile
index a0520e0..746c849 100644
--- a/src/testdir/Makefile
+++ b/src/testdir/Makefile
@@ -73,7 +73,7 @@
 # 	make test_largefile
 $(NEW_TESTS):
 	rm -f $@.res test.log messages
-	@MAKEFLAGS=--no-print-directory $(MAKE) -f Makefile $@.res
+	@MAKEFLAGS=--no-print-directory $(MAKE) -f Makefile $@.res VIMPROG=$(VIMPROG) XXDPROG=$(XXDPROG) SCRIPTSOURCE=$(SCRIPTSOURCE)
 	@cat messages
 	@if test -f test.log; then \
 		exit 1; \
diff --git a/src/testdir/README.txt b/src/testdir/README.txt
index 76396fe..d639146 100644
--- a/src/testdir/README.txt
+++ b/src/testdir/README.txt
@@ -25,6 +25,8 @@
 bit faster, because Vim doesn't have to be started, one Vim instance runs many
 tests.
 
+At 4), to run a test in GUI, add "GUI_FLAG=-g" to the make command.
+
 
 What you can use (see test_assert.vim for an example):
 
diff --git a/src/version.c b/src/version.c
index 75e02ff..58b84d0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    290,
+/**/
     289,
 /**/
     288,