tests/test-mq-header-from.t

bundle2: implement consume() API on unbundlepart

We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.

A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.

In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.

The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:

! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)

Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.

Differential Revision: https://phab.mercurial-scm.org/D1388

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ echo "[diff]" >> $HGRCPATH
  $ echo "nodates=true" >> $HGRCPATH
  $ catlog() {
  >     cat .hg/patches/$1.patch | sed -e "s/^diff \-r [0-9a-f]* /diff -r ... /" \
  >                                    -e "s/^\(# Parent \).*/\1/"
  >     hg log --template "{rev}: {desc} - {author}\n"
  > }
  $ runtest() {
  >     echo ==== init
  >     hg init a
  >     cd a
  >     hg qinit
  > 
  > 
  >     echo ==== qnew -U
  >     hg qnew -U 1.patch
  >     catlog 1
  > 
  >     echo ==== qref
  >     echo "1" >1
  >     hg add
  >     hg qref
  >     catlog 1
  > 
  >     echo ==== qref -u
  >     hg qref -u mary
  >     catlog 1
  > 
  >     echo ==== qnew
  >     hg qnew 2.patch
  >     echo "2" >2
  >     hg add
  >     hg qref
  >     catlog 2
  > 
  >     echo ==== qref -u
  >     hg qref -u jane
  >     catlog 2
  > 
  > 
  >     echo ==== qnew -U -m
  >     hg qnew -U -m "Three" 3.patch
  >     catlog 3
  > 
  >     echo ==== qref
  >     echo "3" >3
  >     hg add
  >     hg qref
  >     catlog 3
  > 
  >     echo ==== qref -m
  >     hg qref -m "Drei"
  >     catlog 3
  > 
  >     echo ==== qref -u
  >     hg qref -u mary
  >     catlog 3
  > 
  >     echo ==== qref -u -m
  >     hg qref -u maria -m "Three (again)"
  >     catlog 3
  > 
  >     echo ==== qnew -m
  >     hg qnew -m "Four" 4.patch
  >     echo "4" >4of t
  >     hg add
  >     hg qref
  >     catlog 4
  > 
  >     echo ==== qref -u
  >     hg qref -u jane
  >     catlog 4
  > 
  > 
  >     echo ==== qnew with HG header
  >     hg qnew --config 'mq.plain=true' 5.patch
  >     hg qpop
  >     echo "# HG changeset patch" >>.hg/patches/5.patch
  >     echo "# User johndoe" >>.hg/patches/5.patch
  >     hg qpush 2>&1 | grep 'now at'
  >     catlog 5
  > 
  >     echo ==== hg qref
  >     echo "5" >5
  >     hg add
  >     hg qref
  >     catlog 5
  > 
  >     echo ==== hg qref -U
  >     hg qref -U
  >     catlog 5
  > 
  >     echo ==== hg qref -u
  >     hg qref -u johndeere
  >     catlog 5
  > 
  > 
  >     echo ==== qnew with plain header
  >     hg qnew --config 'mq.plain=true' -U 6.patch
  >     hg qpop
  >     hg qpush 2>&1 | grep 'now at'
  >     catlog 6
  > 
  >     echo ==== hg qref
  >     echo "6" >6
  >     hg add
  >     hg qref
  >     catlog 6
  > 
  >     echo ==== hg qref -U
  >     hg qref -U
  >     catlog 6
  > 
  >     echo ==== hg qref -u
  >     hg qref -u johndeere
  >     catlog 6
  > 
  > 
  >     echo ==== "qpop -a / qpush -a"
  >     hg qpop -a
  >     hg qpush -a
  >     hg log --template "{rev}: {desc} - {author}\n"
  > }

======= plain headers

  $ echo "[mq]" >> $HGRCPATH
  $ echo "plain=true" >> $HGRCPATH
  $ mkdir sandbox
  $ (cd sandbox ; runtest)
  ==== init
  ==== qnew -U
  From: test
  
  0: [mq]: 1.patch - test
  ==== qref
  adding 1
  From: test
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: [mq]: 1.patch - test
  ==== qref -u
  From: mary
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: [mq]: 1.patch - mary
  ==== qnew
  adding 2
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: [mq]: 2.patch - test
  0: [mq]: 1.patch - mary
  ==== qref -u
  From: jane
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew -U -m
  From: test
  
  Three
  
  2: Three - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref
  adding 3
  From: test
  
  Three
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Three - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -m
  From: test
  
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Drei - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u
  From: mary
  
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Drei - mary
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u -m
  From: maria
  
  Three (again)
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew -m
  adding 4of
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: Four - test
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u
  From: jane
  
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew with HG header
  popping 5.patch
  now at: 4.patch
  now at: 5.patch
  # HG changeset patch
  # User johndoe
  4: imported patch 5.patch - johndoe
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref
  adding 5
  # HG changeset patch
  # User johndoe
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - johndoe
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -U
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - test
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -u
  # HG changeset patch
  # User johndeere
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew with plain header
  popping 6.patch
  now at: 5.patch
  now at: 6.patch
  From: test
  
  5: imported patch 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref
  adding 6
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -U
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -u
  From: johndeere
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - johndeere
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qpop -a / qpush -a
  popping 6.patch
  popping 5.patch
  popping 4.patch
  popping 3.patch
  popping 2.patch
  popping 1.patch
  patch queue now empty
  applying 1.patch
  applying 2.patch
  applying 3.patch
  applying 4.patch
  applying 5.patch
  applying 6.patch
  now at: 6.patch
  5: imported patch 6.patch - johndeere
  4: imported patch 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: imported patch 2.patch - jane
  0: imported patch 1.patch - mary
  $ rm -r sandbox

======= hg headers

  $ echo "plain=false" >> $HGRCPATH
  $ mkdir sandbox
  $ (cd sandbox ; runtest)
  ==== init
  ==== qnew -U
  # HG changeset patch
  # User test
  # Parent 
  
  0: [mq]: 1.patch - test
  ==== qref
  adding 1
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: [mq]: 1.patch - test
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: [mq]: 1.patch - mary
  ==== qnew
  adding 2
  # HG changeset patch
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: [mq]: 2.patch - test
  0: [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew -U -m
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  2: Three - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref
  adding 3
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Three - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -m
  # HG changeset patch
  # User test
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Drei - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Drei - mary
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u -m
  # HG changeset patch
  # User maria
  # Parent 
  Three (again)
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew -m
  adding 4of
  # HG changeset patch
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: Four - test
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew with HG header
  popping 5.patch
  now at: 4.patch
  now at: 5.patch
  # HG changeset patch
  # User johndoe
  4: imported patch 5.patch - johndoe
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref
  adding 5
  # HG changeset patch
  # User johndoe
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - johndoe
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -U
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - test
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -u
  # HG changeset patch
  # User johndeere
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew with plain header
  popping 6.patch
  now at: 5.patch
  now at: 6.patch
  From: test
  
  5: imported patch 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref
  adding 6
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -U
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -u
  From: johndeere
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - johndeere
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qpop -a / qpush -a
  popping 6.patch
  popping 5.patch
  popping 4.patch
  popping 3.patch
  popping 2.patch
  popping 1.patch
  patch queue now empty
  applying 1.patch
  applying 2.patch
  applying 3.patch
  applying 4.patch
  applying 5.patch
  applying 6.patch
  now at: 6.patch
  5: imported patch 6.patch - johndeere
  4: imported patch 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: imported patch 2.patch - jane
  0: imported patch 1.patch - mary
  $ rm -r sandbox
  $ runtest
  ==== init
  ==== qnew -U
  # HG changeset patch
  # User test
  # Parent 
  
  0: [mq]: 1.patch - test
  ==== qref
  adding 1
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: [mq]: 1.patch - test
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  
  diff -r ... 1
  --- /dev/null
  +++ b/1
  @@ -0,0 +1,1 @@
  +1
  0: [mq]: 1.patch - mary
  ==== qnew
  adding 2
  # HG changeset patch
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: [mq]: 2.patch - test
  0: [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  
  diff -r ... 2
  --- /dev/null
  +++ b/2
  @@ -0,0 +1,1 @@
  +2
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew -U -m
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  2: Three - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref
  adding 3
  # HG changeset patch
  # User test
  # Parent 
  Three
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Three - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -m
  # HG changeset patch
  # User test
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Drei - test
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User mary
  # Parent 
  Drei
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Drei - mary
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u -m
  # HG changeset patch
  # User maria
  # Parent 
  Three (again)
  
  diff -r ... 3
  --- /dev/null
  +++ b/3
  @@ -0,0 +1,1 @@
  +3
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew -m
  adding 4of
  # HG changeset patch
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: Four - test
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qref -u
  # HG changeset patch
  # User jane
  # Parent 
  Four
  
  diff -r ... 4of
  --- /dev/null
  +++ b/4of
  @@ -0,0 +1,1 @@
  +4 t
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew with HG header
  popping 5.patch
  now at: 4.patch
  now at: 5.patch
  # HG changeset patch
  # User johndoe
  4: imported patch 5.patch - johndoe
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref
  adding 5
  # HG changeset patch
  # User johndoe
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - johndoe
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -U
  # HG changeset patch
  # User test
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - test
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -u
  # HG changeset patch
  # User johndeere
  # Parent 
  
  diff -r ... 5
  --- /dev/null
  +++ b/5
  @@ -0,0 +1,1 @@
  +5
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qnew with plain header
  popping 6.patch
  now at: 5.patch
  now at: 6.patch
  From: test
  
  5: imported patch 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref
  adding 6
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -U
  From: test
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - test
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== hg qref -u
  From: johndeere
  
  diff -r ... 6
  --- /dev/null
  +++ b/6
  @@ -0,0 +1,1 @@
  +6
  5: [mq]: 6.patch - johndeere
  4: [mq]: 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: [mq]: 2.patch - jane
  0: [mq]: 1.patch - mary
  ==== qpop -a / qpush -a
  popping 6.patch
  popping 5.patch
  popping 4.patch
  popping 3.patch
  popping 2.patch
  popping 1.patch
  patch queue now empty
  applying 1.patch
  applying 2.patch
  applying 3.patch
  applying 4.patch
  applying 5.patch
  applying 6.patch
  now at: 6.patch
  5: imported patch 6.patch - johndeere
  4: imported patch 5.patch - johndeere
  3: Four - jane
  2: Three (again) - maria
  1: imported patch 2.patch - jane
  0: imported patch 1.patch - mary

  $ cd ..