patch 8.2.1794: no falsy Coalescing operator
Problem: No falsy Coalescing operator.
Solution: Add the "??" operator. Fix mistake with function argument count.
diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index f1f358a..a8dbe1a 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -1326,6 +1326,33 @@
delete('Xdisassemble')
enddef
+def s:FalsyOp()
+ echo g:flag ?? "yes"
+ echo [] ?? "empty list"
+ echo "" ?? "empty string"
+enddef
+
+def Test_dsassemble_falsy_op()
+ var res = execute('disass s:FalsyOp')
+ assert_match('\<SNR>\d*_FalsyOp\_s*' ..
+ 'echo g:flag ?? "yes"\_s*' ..
+ '0 LOADG g:flag\_s*' ..
+ '1 JUMP_AND_KEEP_IF_TRUE -> 3\_s*' ..
+ '2 PUSHS "yes"\_s*' ..
+ '3 ECHO 1\_s*' ..
+ 'echo \[\] ?? "empty list"\_s*' ..
+ '4 NEWLIST size 0\_s*' ..
+ '5 JUMP_AND_KEEP_IF_TRUE -> 7\_s*' ..
+ '6 PUSHS "empty list"\_s*' ..
+ '7 ECHO 1\_s*' ..
+ 'echo "" ?? "empty string"\_s*' ..
+ '\d\+ PUSHS "empty string"\_s*' ..
+ '\d\+ ECHO 1\_s*' ..
+ '\d\+ PUSHNR 0\_s*' ..
+ '\d\+ RETURN',
+ res)
+enddef
+
def Test_disassemble_compare_const()
var cases = [
['"xx" == "yy"', false],