patch 7.4.1916
Problem: No proper test for what 7.4.1906 fixes.
Solution: Add a test for reading many lines.
diff --git a/src/testdir/test_channel.vim b/src/testdir/test_channel.vim
index d65e528..9d68a14 100644
--- a/src/testdir/test_channel.vim
+++ b/src/testdir/test_channel.vim
@@ -1335,6 +1335,20 @@
call test_garbagecollect_now()
endfunc
+func Test_collapse_buffers()
+ if !executable('cat')
+ return
+ endif
+ sp test_channel.vim
+ let g:linecount = line('$')
+ close
+ split testout
+ 1,$delete
+ call job_start('cat test_channel.vim', {'out_io': 'buffer', 'out_name': 'testout'})
+ call s:waitFor('line("$") > g:linecount')
+ call assert_true(line('$') > g:linecount)
+ bwipe!
+endfunc
" Uncomment this to see what happens, output is in src/testdir/channellog.