revlog: generate trivial deltas against null revision To avoid extra memory usage and performance issues with large files, generate a trivial delta header for deltas against the null revision rather than calling the usual delta generator. We append the delta header to meta rather than prepending it to data to avoid a large allocate and copy.

adding base
abort: qdelete requires at least one revision or patch name
abort: cannot delete applied patch c
Now at: b
a
b
a
b
series
status
Now at: a
a
b
series
status
1 [mq]: a
0 base
abort: cannot delete revision 3 above applied patches
f
4 [mq]: f
3 [mq]: e
2 [mq]: d
1 [mq]: a
0 base