tests/test-template-basic.t

sparse-revlog: implement algorithm to write sparse delta chains (issue5480)

The classic behavior of revlog._isgooddeltainfo is to consider the span size
of the whole delta chain, and limit it to 4 * textlen.
Once sparse-revlog writing is allowed (and enforced with a requirement),
revlog._isgooddeltainfo considers the span of the largest chunk as the
distance used in the verification, instead of using the span of the whole
delta chain.

In order to compute the span of the largest chunk, we need to slice into
chunks a chain with the new revision at the top of the revlog, and take the
maximal span of these chunks. The sparse read density is a parameter to the
slicing, as it will stop when the global read density reaches this threshold.
For instance, a density of 50% means that 2 of 4 read bytes are actually used
for the reconstruction of the revision (the others are part of other chains).

This allows a new revision to be potentially stored with a diff against
another revision anywhere in the history, instead of forcing it in the last 4
* textlen. The result is a much better compression on repositories that have
many concurrent branches. Here are a comparison between using deltas from
current upstream (aggressive-merge-deltas on by default) and deltas from a
sparse-revlog

Comparison of `.hg/store/` size:

    mercurial (6.74% merges):
        before:     46,831,873 bytes
        after:      46,795,992 bytes (no relevant change)
    pypy (8.30% merges):
        before:    333,524,651 bytes
        after:     308,417,511 bytes -8%
    netbeans (34.21% merges):
        before:  1,141,847,554 bytes
        after:   1,131,093,161 bytes -1%
    mozilla-central (4.84% merges):
        before:  2,344,248,850 bytes
        after:   2,328,459,258 bytes -1%
    large-private-repo-A (merge 19.73%)
        before: 41,510,550,163 bytes
        after:   8,121,763,428 bytes -80%
    large-private-repo-B (23.77%)
        before: 58,702,221,709 bytes
        after:   8,351,588,828 bytes -76%

Comparison of `00manifest.d` size:

    mercurial (6.74% merges):
        before:      6,143,044 bytes
        after:       6,107,163 bytes
    pypy (8.30% merges):
        before:     52,941,780 bytes
        after:      27,834,082 bytes -48%
    netbeans (34.21% merges):
        before:    130,088,982 bytes
        after:     119,337,636 bytes -10%
    mozilla-central (4.84% merges):
        before:    215,096,339 bytes
        after:     199,496,863 bytes -8%
    large-private-repo-A (merge 19.73%)
        before: 33,725,285,081 bytes
        after:     390,302,545 bytes -99%
    large-private-repo-B (23.77%)
        before: 49,457,701,645 bytes
        after:   1,366,752,187 bytes -97%


The better delta chains provide a performance boost in relevant repositories:

    pypy, bundling 1000 revisions:
        before: 1.670s
        after:  1.149s -31%

Unbundling got a bit slower. probably because the sparse algorithm is still
pure
python.

    pypy, unbundling 1000 revisions:
        before: 4.062s
        after:  4.507s +10%

Performance of bundle/unbundle in repository with few concurrent branches (eg:
mercurial) are unaffected.

No significant differences have been noticed then timing `hg push` and `hg
pull` locally. More state timings are being gathered.

Same as for aggressive-merge-delta, better delta comes with longer delta
chains. Longer chains have a performance impact. For example. The length of
the chain needed to get the manifest of pypy's tip moves from 82 item to 1929
items. This moves the restore time from 3.88ms to 11.3ms.

Delta chain length is an independent issue that affects repository without
this changes. It will be dealt with independently.

No significant differences have been observed on repositories where
`sparse-revlog` have not much effect (mercurial, unity, netbeans). On pypy,
small differences have been observed on some operation affected by delta chain
building and retrieval.


    pypy, perfmanifest
        before: 0.006162s
        after:  0.017899s +190%

    pypy, commit:
        before: 0.382
        after:  0.376 -1%

    pypy, status:
        before: 0.157
        after:  0.168 +7%

More comprehensive and stable timing comparisons are in progress.

Test template syntax and basic functionality
============================================

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg add a
  $ echo line 1 > b
  $ echo line 2 >> b
  $ hg commit -l b -d '1000000 0' -u 'User Name <user@hostname>'

  $ hg add b
  $ echo other 1 > c
  $ echo other 2 >> c
  $ echo >> c
  $ echo other 3 >> c
  $ hg commit -l c -d '1100000 0' -u 'A. N. Other <other@place>'

  $ hg add c
  $ hg commit -m 'no person' -d '1200000 0' -u 'other@place'
  $ echo c >> c
  $ hg commit -m 'no user, no domain' -d '1300000 0' -u 'person'

  $ echo foo > .hg/branch
  $ hg commit -m 'new branch' -d '1400000 0' -u 'person'

  $ hg co -q 3
  $ echo other 4 >> d
  $ hg add d
  $ hg commit -m 'new head' -d '1500000 0' -u 'person'

  $ hg merge -q foo
  $ hg commit -m 'merge' -d '1500001 0' -u 'person'

Test arithmetic operators have the right precedence:

  $ hg log -l 1 -T '{date(date, "%Y") + 5 * 10} {date(date, "%Y") - 2 * 3}\n'
  2020 1964
  $ hg log -l 1 -T '{date(date, "%Y") * 5 + 10} {date(date, "%Y") * 3 - 2}\n'
  9860 5908

Test division:

  $ hg debugtemplate -r0 -v '{5 / 2} {mod(5, 2)}\n'
  (template
    (/
      (integer '5')
      (integer '2'))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (integer '5')
        (integer '2')))
    (string '\n'))
  * keywords: 
  * functions: mod
  2 1
  $ hg debugtemplate -r0 -v '{5 / -2} {mod(5, -2)}\n'
  (template
    (/
      (integer '5')
      (negate
        (integer '2')))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (integer '5')
        (negate
          (integer '2'))))
    (string '\n'))
  * keywords: 
  * functions: mod
  -3 -1
  $ hg debugtemplate -r0 -v '{-5 / 2} {mod(-5, 2)}\n'
  (template
    (/
      (negate
        (integer '5'))
      (integer '2'))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (negate
          (integer '5'))
        (integer '2')))
    (string '\n'))
  * keywords: 
  * functions: mod
  -3 1
  $ hg debugtemplate -r0 -v '{-5 / -2} {mod(-5, -2)}\n'
  (template
    (/
      (negate
        (integer '5'))
      (negate
        (integer '2')))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (negate
          (integer '5'))
        (negate
          (integer '2'))))
    (string '\n'))
  * keywords: 
  * functions: mod
  2 -1

Filters bind closer than arithmetic:

  $ hg debugtemplate -r0 -v '{revset(".")|count - 1}\n'
  (template
    (-
      (|
        (func
          (symbol 'revset')
          (string '.'))
        (symbol 'count'))
      (integer '1'))
    (string '\n'))
  * keywords: 
  * functions: count, revset
  0

But negate binds closer still:

  $ hg debugtemplate -r0 -v '{1-3|stringify}\n'
  (template
    (-
      (integer '1')
      (|
        (integer '3')
        (symbol 'stringify')))
    (string '\n'))
  * keywords: 
  * functions: stringify
  hg: parse error: arithmetic only defined on integers
  [255]
  $ hg debugtemplate -r0 -v '{-3|stringify}\n'
  (template
    (|
      (negate
        (integer '3'))
      (symbol 'stringify'))
    (string '\n'))
  * keywords: 
  * functions: stringify
  -3

Filters bind as close as map operator:

  $ hg debugtemplate -r0 -v '{desc|splitlines % "{line}\n"}'
  (template
    (%
      (|
        (symbol 'desc')
        (symbol 'splitlines'))
      (template
        (symbol 'line')
        (string '\n'))))
  * keywords: desc, line
  * functions: splitlines
  line 1
  line 2

Keyword arguments:

  $ hg debugtemplate -r0 -v '{foo=bar|baz}'
  (template
    (keyvalue
      (symbol 'foo')
      (|
        (symbol 'bar')
        (symbol 'baz'))))
  * keywords: bar, foo
  * functions: baz
  hg: parse error: can't use a key-value pair in this context
  [255]

  $ hg debugtemplate '{pad("foo", width=10, left=true)}\n'
         foo

Call function which takes named arguments by filter syntax:

  $ hg debugtemplate '{" "|separate}'
  $ hg debugtemplate '{("not", "an", "argument", "list")|separate}'
  hg: parse error: unknown method 'list'
  [255]

Second branch starting at nullrev:

  $ hg update null
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  $ echo second > second
  $ hg add second
  $ hg commit -m second -d '1000000 0' -u 'User Name <user@hostname>'
  created new head

  $ echo third > third
  $ hg add third
  $ hg mv second fourth
  $ hg commit -m third -d "2020-01-01 10:01"

  $ hg log --template '{join(file_copies, ",\n")}\n' -r .
  fourth (second)
  $ hg log -T '{file_copies % "{source} -> {name}\n"}' -r .
  second -> fourth
  $ hg log -T '{rev} {ifcontains("fourth", file_copies, "t", "f")}\n' -r .:7
  8 t
  7 f

Internal resources shouldn't be exposed (issue5699):

  $ hg log -r. -T '{cache}{ctx}{repo}{revcache}{templ}{ui}'

Never crash on internal resource not available:

  $ hg --cwd .. debugtemplate '{"c0bebeef"|shortest}\n'
  abort: template resource not available: repo
  [255]

  $ hg config -T '{author}'

Quoting for ui.logtemplate

  $ hg tip --config "ui.logtemplate={rev}\n"
  8
  $ hg tip --config "ui.logtemplate='{rev}\n'"
  8
  $ hg tip --config 'ui.logtemplate="{rev}\n"'
  8
  $ hg tip --config 'ui.logtemplate=n{rev}\n'
  n8

Check that recursive reference does not fall into RuntimeError (issue4758):

 common mistake:

  $ cat << EOF > issue4758
  > changeset = '{changeset}\n'
  > EOF
  $ hg log --style ./issue4758
  abort: recursive reference 'changeset' in template
  [255]

 circular reference:

  $ cat << EOF > issue4758
  > changeset = '{foo}'
  > foo = '{changeset}'
  > EOF
  $ hg log --style ./issue4758
  abort: recursive reference 'foo' in template
  [255]

 buildmap() -> gettemplate(), where no thunk was made:

  $ cat << EOF > issue4758
  > changeset = '{files % changeset}\n'
  > EOF
  $ hg log --style ./issue4758
  abort: recursive reference 'changeset' in template
  [255]

 not a recursion if a keyword of the same name exists:

  $ cat << EOF > issue4758
  > changeset = '{tags % rev}'
  > rev = '{rev} {tag}\n'
  > EOF
  $ hg log --style ./issue4758 -r tip
  8 tip

Set up phase:

  $ hg phase -r 5 --public
  $ hg phase -r 7 --secret --force

Add a dummy commit to make up for the instability of the above:

  $ echo a > a
  $ hg add a
  $ hg ci -m future

Add a commit that does all possible modifications at once

  $ echo modify >> third
  $ touch b
  $ hg add b
  $ hg mv fourth fifth
  $ hg rm a
  $ hg ci -m "Modify, add, remove, rename"

Error on syntax:

  $ cat <<EOF > t
  > changeset = '{c}'
  > c = q
  > x = "f
  > EOF
  $ echo '[ui]' > .hg/hgrc
  $ echo 'style = t' >> .hg/hgrc
  $ hg log
  hg: parse error at t:3: unmatched quotes
  [255]

  $ hg log -T '{date'
  hg: parse error at 1: unterminated template expansion
  ({date
    ^ here)
  [255]
  $ hg log -T '{date(}'
  hg: parse error at 6: not a prefix: end
  ({date(}
         ^ here)
  [255]
  $ hg log -T '{date)}'
  hg: parse error at 5: invalid token
  ({date)}
        ^ here)
  [255]
  $ hg log -T '{date date}'
  hg: parse error at 6: invalid token
  ({date date}
         ^ here)
  [255]

  $ hg log -T '{}'
  hg: parse error at 1: not a prefix: end
  ({}
    ^ here)
  [255]
  $ hg debugtemplate -v '{()}'
  (template
    (group
      None))
  * keywords: 
  * functions: 
  hg: parse error: missing argument
  [255]

Behind the scenes, this would throw TypeError without intype=bytes

  $ hg log -l 3 --template '{date|obfuscate}\n'
  &#48;&#46;&#48;&#48;
  &#48;&#46;&#48;&#48;
  &#49;&#53;&#55;&#55;&#56;&#55;&#50;&#56;&#54;&#48;&#46;&#48;&#48;

Behind the scenes, this will throw a ValueError

  $ hg log -l 3 --template 'line: {desc|shortdate}\n'
  hg: parse error: invalid date: 'Modify, add, remove, rename'
  (template filter 'shortdate' is not compatible with keyword 'desc')
  [255]

Behind the scenes, this would throw AttributeError without intype=bytes

  $ hg log -l 3 --template 'line: {date|escape}\n'
  line: 0.00
  line: 0.00
  line: 1577872860.00

  $ hg log -l 3 --template 'line: {extras|localdate}\n'
  hg: parse error: localdate expects a date information
  [255]

Behind the scenes, this will throw ValueError

  $ hg tip --template '{author|email|date}\n'
  hg: parse error: date expects a date information
  [255]

  $ hg tip -T '{author|email|shortdate}\n'
  hg: parse error: invalid date: 'test'
  (template filter 'shortdate' is not compatible with keyword 'author')
  [255]

  $ hg tip -T '{get(extras, "branch")|shortdate}\n'
  hg: parse error: invalid date: 'default'
  (incompatible use of template filter 'shortdate')
  [255]

Error in nested template:

  $ hg log -T '{"date'
  hg: parse error at 2: unterminated string
  ({"date
     ^ here)
  [255]

  $ hg log -T '{"foo{date|?}"}'
  hg: parse error at 11: syntax error
  ({"foo{date|?}"}
              ^ here)
  [255]

Thrown an error if a template function doesn't exist

  $ hg tip --template '{foo()}\n'
  hg: parse error: unknown function 'foo'
  [255]

  $ cd ..

Set up latesttag repository:

  $ hg init latesttag
  $ cd latesttag

  $ echo a > file
  $ hg ci -Am a -d '0 0'
  adding file

  $ echo b >> file
  $ hg ci -m b -d '1 0'

  $ echo c >> head1
  $ hg ci -Am h1c -d '2 0'
  adding head1

  $ hg update -q 1
  $ echo d >> head2
  $ hg ci -Am h2d -d '3 0'
  adding head2
  created new head

  $ echo e >> head2
  $ hg ci -m h2e -d '4 0'

  $ hg merge -q
  $ hg ci -m merge -d '5 -3600'

  $ hg tag -r 1 -m t1 -d '6 0' t1
  $ hg tag -r 2 -m t2 -d '7 0' t2
  $ hg tag -r 3 -m t3 -d '8 0' t3
  $ hg tag -r 4 -m t4 -d '4 0' t4 # older than t2, but should not matter
  $ hg tag -r 5 -m t5 -d '9 0' t5
  $ hg tag -r 3 -m at3 -d '10 0' at3

  $ cd ..

Test new-style inline templating:

  $ hg log -R latesttag -r tip --template 'modified files: {file_mods % " {file}\n"}\n'
  modified files:  .hgtags
  

  $ hg log -R latesttag -r tip -T '{rev % "a"}\n'
  hg: parse error: 11 is not iterable of mappings
  (keyword 'rev' does not support map operation)
  [255]
  $ hg log -R latesttag -r tip -T '{get(extras, "unknown") % "a"}\n'
  hg: parse error: None is not iterable of mappings
  [255]
  $ hg log -R latesttag -r tip -T '{extras % "{key}\n" % "{key}\n"}'
  hg: parse error: list of strings is not mappable
  [255]

Test new-style inline templating of non-list/dict type:

  $ hg log -R latesttag -r tip -T '{manifest}\n'
  11:2bc6e9006ce2
  $ hg log -R latesttag -r tip -T 'string length: {manifest|count}\n'
  string length: 15
  $ hg log -R latesttag -r tip -T '{manifest % "{rev}:{node}"}\n'
  11:2bc6e9006ce29882383a22d39fd1f4e66dd3e2fc

  $ hg log -R latesttag -r tip -T '{get(extras, "branch") % "{key}: {value}\n"}'
  branch: default
  $ hg log -R latesttag -r tip -T '{get(extras, "unknown") % "{key}\n"}'
  hg: parse error: None is not iterable of mappings
  [255]
  $ hg log -R latesttag -r tip -T '{min(extras) % "{key}: {value}\n"}'
  branch: default
  $ hg log -R latesttag -l1 -T '{min(revset("0:9")) % "{rev}:{node|short}\n"}'
  0:ce3cec86e6c2
  $ hg log -R latesttag -l1 -T '{max(revset("0:9")) % "{rev}:{node|short}\n"}'
  9:fbc7cd862e9c

Test dot operator precedence:

  $ hg debugtemplate -R latesttag -r0 -v '{manifest.node|short}\n'
  (template
    (|
      (.
        (symbol 'manifest')
        (symbol 'node'))
      (symbol 'short'))
    (string '\n'))
  * keywords: manifest, node, rev
  * functions: formatnode, short
  89f4071fec70

 (the following examples are invalid, but seem natural in parsing POV)

  $ hg debugtemplate -R latesttag -r0 -v '{foo|bar.baz}\n' 2> /dev/null
  (template
    (|
      (symbol 'foo')
      (.
        (symbol 'bar')
        (symbol 'baz')))
    (string '\n'))
  [255]
  $ hg debugtemplate -R latesttag -r0 -v '{foo.bar()}\n' 2> /dev/null
  (template
    (.
      (symbol 'foo')
      (func
        (symbol 'bar')
        None))
    (string '\n'))
  * keywords: foo
  * functions: bar
  [255]

Test evaluation of dot operator:

  $ hg log -R latesttag -l1 -T '{min(revset("0:9")).node}\n'
  ce3cec86e6c26bd9bdfc590a6b92abc9680f1796
  $ hg log -R latesttag -r0 -T '{extras.branch}\n'
  default
  $ hg log -R latesttag -r0 -T '{date.unixtime} {localdate(date, "+0200").tzoffset}\n'
  0 -7200

  $ hg log -R latesttag -l1 -T '{author.invalid}\n'
  hg: parse error: 'test' is not a dictionary
  (keyword 'author' does not support member operation)
  [255]
  $ hg log -R latesttag -l1 -T '{min("abc").invalid}\n'
  hg: parse error: 'a' is not a dictionary
  [255]

Test integer literal:

  $ hg debugtemplate -v '{(0)}\n'
  (template
    (group
      (integer '0'))
    (string '\n'))
  * keywords: 
  * functions: 
  0
  $ hg debugtemplate -v '{(123)}\n'
  (template
    (group
      (integer '123'))
    (string '\n'))
  * keywords: 
  * functions: 
  123
  $ hg debugtemplate -v '{(-4)}\n'
  (template
    (group
      (negate
        (integer '4')))
    (string '\n'))
  * keywords: 
  * functions: 
  -4
  $ hg debugtemplate '{(-)}\n'
  hg: parse error at 3: not a prefix: )
  ({(-)}\n
      ^ here)
  [255]
  $ hg debugtemplate '{(-a)}\n'
  hg: parse error: negation needs an integer argument
  [255]

top-level integer literal is interpreted as symbol (i.e. variable name):

  $ hg debugtemplate -D 1=one -v '{1}\n'
  (template
    (integer '1')
    (string '\n'))
  * keywords: 
  * functions: 
  one
  $ hg debugtemplate -D 1=one -v '{if("t", "{1}")}\n'
  (template
    (func
      (symbol 'if')
      (list
        (string 't')
        (template
          (integer '1'))))
    (string '\n'))
  * keywords: 
  * functions: if
  one
  $ hg debugtemplate -D 1=one -v '{1|stringify}\n'
  (template
    (|
      (integer '1')
      (symbol 'stringify'))
    (string '\n'))
  * keywords: 
  * functions: stringify
  one

unless explicit symbol is expected:

  $ hg log -Ra -r0 -T '{desc|1}\n'
  hg: parse error: expected a symbol, got 'integer'
  [255]
  $ hg log -Ra -r0 -T '{1()}\n'
  hg: parse error: expected a symbol, got 'integer'
  [255]

Test string literal:

  $ hg debugtemplate -Ra -r0 -v '{"string with no template fragment"}\n'
  (template
    (string 'string with no template fragment')
    (string '\n'))
  * keywords: 
  * functions: 
  string with no template fragment
  $ hg debugtemplate -Ra -r0 -v '{"template: {rev}"}\n'
  (template
    (template
      (string 'template: ')
      (symbol 'rev'))
    (string '\n'))
  * keywords: rev
  * functions: 
  template: 0
  $ hg debugtemplate -Ra -r0 -v '{r"rawstring: {rev}"}\n'
  (template
    (string 'rawstring: {rev}')
    (string '\n'))
  * keywords: 
  * functions: 
  rawstring: {rev}
  $ hg debugtemplate -Ra -r0 -v '{files % r"rawstring: {file}"}\n'
  (template
    (%
      (symbol 'files')
      (string 'rawstring: {file}'))
    (string '\n'))
  * keywords: files
  * functions: 
  rawstring: {file}

Test string escaping:

  $ hg log -R latesttag -r 0 --template '>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  >
  <>\n<[>
  <>\n<]>
  <>\n<

  $ hg log -R latesttag -r 0 \
  > --config ui.logtemplate='>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  >
  <>\n<[>
  <>\n<]>
  <>\n<

  $ hg log -R latesttag -r 0 -T esc \
  > --config templates.esc='>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  >
  <>\n<[>
  <>\n<]>
  <>\n<

  $ cat <<'EOF' > esctmpl
  > changeset = '>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  > EOF
  $ hg log -R latesttag -r 0 --style ./esctmpl
  >
  <>\n<[>
  <>\n<]>
  <>\n<

Test string escaping of quotes:

  $ hg log -Ra -r0 -T '{"\""}\n'
  "
  $ hg log -Ra -r0 -T '{"\\\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\\\""}\n'
  \\\"


  $ hg log -Ra -r0 -T '{"\""}\n'
  "
  $ hg log -Ra -r0 -T '{"\\\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\\\""}\n'
  \\\"

Test exception in quoted template. single backslash before quotation mark is
stripped before parsing:

  $ cat <<'EOF' > escquotetmpl
  > changeset = "\" \\" \\\" \\\\" {files % \"{file}\"}\n"
  > EOF
  $ cd latesttag
  $ hg log -r 2 --style ../escquotetmpl
  " \" \" \\" head1

  $ hg log -r 2 -T esc --config templates.esc='"{\"valid\"}\n"'
  valid
  $ hg log -r 2 -T esc --config templates.esc="'"'{\'"'"'valid\'"'"'}\n'"'"
  valid

Test compatibility with 2.9.2-3.4 of escaped quoted strings in nested
_evalifliteral() templates (issue4733):

  $ hg log -r 2 -T '{if(rev, "\"{rev}")}\n'
  "2
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"\\\"{rev}\")}")}\n'
  "2
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"{if(rev, \\\"\\\\\\\"{rev}\\\")}\")}")}\n'
  "2

  $ hg log -r 2 -T '{if(rev, "\\\"")}\n'
  \"
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"\\\\\\\"\")}")}\n'
  \"
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"{if(rev, \\\"\\\\\\\\\\\\\\\"\\\")}\")}")}\n'
  \"

  $ hg log -r 2 -T '{if(rev, r"\\\"")}\n'
  \\\"
  $ hg log -r 2 -T '{if(rev, "{if(rev, r\"\\\\\\\"\")}")}\n'
  \\\"
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"{if(rev, r\\\"\\\\\\\\\\\\\\\"\\\")}\")}")}\n'
  \\\"

escaped single quotes and errors:

  $ hg log -r 2 -T "{if(rev, '{if(rev, \'foo\')}')}"'\n'
  foo
  $ hg log -r 2 -T "{if(rev, '{if(rev, r\'foo\')}')}"'\n'
  foo
  $ hg log -r 2 -T '{if(rev, "{if(rev, \")}")}\n'
  hg: parse error at 21: unterminated string
  ({if(rev, "{if(rev, \")}")}\n
                        ^ here)
  [255]
  $ hg log -r 2 -T '{if(rev, \"\\"")}\n'
  hg: parse error: trailing \ in string
  [255]
  $ hg log -r 2 -T '{if(rev, r\"\\"")}\n'
  hg: parse error: trailing \ in string
  [255]

  $ cd ..

Test leading backslashes:

  $ cd latesttag
  $ hg log -r 2 -T '\{rev} {files % "\{file}"}\n'
  {rev} {file}
  $ hg log -r 2 -T '\\{rev} {files % "\\{file}"}\n'
  \2 \head1
  $ hg log -r 2 -T '\\\{rev} {files % "\\\{file}"}\n'
  \{rev} \{file}
  $ cd ..

Test leading backslashes in "if" expression (issue4714):

  $ cd latesttag
  $ hg log -r 2 -T '{if("1", "\{rev}")} {if("1", r"\{rev}")}\n'
  {rev} \{rev}
  $ hg log -r 2 -T '{if("1", "\\{rev}")} {if("1", r"\\{rev}")}\n'
  \2 \\{rev}
  $ hg log -r 2 -T '{if("1", "\\\{rev}")} {if("1", r"\\\{rev}")}\n'
  \{rev} \\\{rev}
  $ cd ..

"string-escape"-ed "\x5c\x786e" becomes r"\x6e" (once) or r"n" (twice)

  $ hg log -R a -r 0 --template '{if("1", "\x5c\x786e", "NG")}\n'
  \x6e
  $ hg log -R a -r 0 --template '{if("1", r"\x5c\x786e", "NG")}\n'
  \x5c\x786e
  $ hg log -R a -r 0 --template '{if("", "NG", "\x5c\x786e")}\n'
  \x6e
  $ hg log -R a -r 0 --template '{if("", "NG", r"\x5c\x786e")}\n'
  \x5c\x786e

  $ hg log -R a -r 2 --template '{ifeq("no perso\x6e", desc, "\x5c\x786e", "NG")}\n'
  \x6e
  $ hg log -R a -r 2 --template '{ifeq(r"no perso\x6e", desc, "NG", r"\x5c\x786e")}\n'
  \x5c\x786e
  $ hg log -R a -r 2 --template '{ifeq(desc, "no perso\x6e", "\x5c\x786e", "NG")}\n'
  \x6e
  $ hg log -R a -r 2 --template '{ifeq(desc, r"no perso\x6e", "NG", r"\x5c\x786e")}\n'
  \x5c\x786e

  $ hg log -R a -r 8 --template '{join(files, "\n")}\n'
  fourth
  second
  third
  $ hg log -R a -r 8 --template '{join(files, r"\n")}\n'
  fourth\nsecond\nthird

  $ hg log -R a -r 2 --template '{rstdoc("1st\n\n2nd", "htm\x6c")}'
  <p>
  1st
  </p>
  <p>
  2nd
  </p>
  $ hg log -R a -r 2 --template '{rstdoc(r"1st\n\n2nd", "html")}'
  <p>
  1st\n\n2nd
  </p>
  $ hg log -R a -r 2 --template '{rstdoc("1st\n\n2nd", r"htm\x6c")}'
  1st
  
  2nd

  $ hg log -R a -r 2 --template '{strip(desc, "\x6e")}\n'
  o perso
  $ hg log -R a -r 2 --template '{strip(desc, r"\x6e")}\n'
  no person
  $ hg log -R a -r 2 --template '{strip("no perso\x6e", "\x6e")}\n'
  o perso
  $ hg log -R a -r 2 --template '{strip(r"no perso\x6e", r"\x6e")}\n'
  no perso

  $ hg log -R a -r 2 --template '{sub("\\x6e", "\x2d", desc)}\n'
  -o perso-
  $ hg log -R a -r 2 --template '{sub(r"\\x6e", "-", desc)}\n'
  no person
  $ hg log -R a -r 2 --template '{sub("n", r"\\x2d", desc)}\n'
  \x2do perso\x2d
  $ hg log -R a -r 2 --template '{sub("n", "\x2d", "no perso\x6e")}\n'
  -o perso-
  $ hg log -R a -r 2 --template '{sub("n", r"\\x2d", r"no perso\x6e")}\n'
  \x2do perso\x6e

  $ hg log -R a -r 8 --template '{files % "{file}\n"}'
  fourth
  second
  third

Test string escaping in nested expression:

  $ hg log -R a -r 8 --template '{ifeq(r"\x6e", if("1", "\x5c\x786e"), join(files, "\x5c\x786e"))}\n'
  fourth\x6esecond\x6ethird
  $ hg log -R a -r 8 --template '{ifeq(if("1", r"\x6e"), "\x5c\x786e", join(files, "\x5c\x786e"))}\n'
  fourth\x6esecond\x6ethird

  $ hg log -R a -r 8 --template '{join(files, ifeq(branch, "default", "\x5c\x786e"))}\n'
  fourth\x6esecond\x6ethird
  $ hg log -R a -r 8 --template '{join(files, ifeq(branch, "default", r"\x5c\x786e"))}\n'
  fourth\x5c\x786esecond\x5c\x786ethird

  $ hg log -R a -r 3:4 --template '{rev}:{sub(if("1", "\x6e"), ifeq(branch, "foo", r"\x5c\x786e", "\x5c\x786e"), desc)}\n'
  3:\x6eo user, \x6eo domai\x6e
  4:\x5c\x786eew bra\x5c\x786ech

Test quotes in nested expression are evaluated just like a $(command)
substitution in POSIX shells:

  $ hg log -R a -r 8 -T '{"{"{rev}:{node|short}"}"}\n'
  8:95c24699272e
  $ hg log -R a -r 8 -T '{"{"\{{rev}} \"{node|short}\""}"}\n'
  {8} "95c24699272e"

Test recursive evaluation:

  $ hg init r
  $ cd r
  $ echo a > a
  $ hg ci -Am '{rev}'
  adding a
  $ hg log -r 0 --template '{if(rev, desc)}\n'
  {rev}
  $ hg log -r 0 --template '{if(rev, "{author} {rev}")}\n'
  test 0

  $ hg branch -q 'text.{rev}'
  $ echo aa >> aa
  $ hg ci -u '{node|short}' -m 'desc to be wrapped desc to be wrapped'

  $ hg log -l1 --template '{fill(desc, "20", author, branch)}'
  {node|short}desc to
  text.{rev}be wrapped
  text.{rev}desc to be
  text.{rev}wrapped (no-eol)
  $ hg log -l1 --template '{fill(desc, "20", "{node|short}:", "text.{rev}:")}'
  bcc7ff960b8e:desc to
  text.1:be wrapped
  text.1:desc to be
  text.1:wrapped (no-eol)
  $ hg log -l1 -T '{fill(desc, date, "", "")}\n'
  hg: parse error: fill expects an integer width
  [255]

  $ hg log -l 1 --template '{sub(r"[0-9]", "-", author)}'
  {node|short} (no-eol)
  $ hg log -l 1 --template '{sub(r"[0-9]", "-", "{node|short}")}'
  bcc-ff---b-e (no-eol)

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > color=
  > [color]
  > mode=ansi
  > text.{rev} = red
  > text.1 = green
  > EOF
  $ hg log --color=always -l 1 --template '{label(branch, "text\n")}'
  \x1b[0;31mtext\x1b[0m (esc)
  $ hg log --color=always -l 1 --template '{label("text.{rev}", "text\n")}'
  \x1b[0;32mtext\x1b[0m (esc)

  $ cd ..

Test bad template with better error message

  $ hg log -Gv -R a --template '{desc|user()}'
  hg: parse error: expected a symbol, got 'func'
  [255]

Test broken string escapes:

  $ hg log -T "bogus\\" -R a
  hg: parse error: trailing \ in string
  [255]
  $ hg log -T "\\xy" -R a
  hg: parse error: invalid \x escape* (glob)
  [255]

Templater supports aliases of symbol and func() styles:

  $ hg clone -q a aliases
  $ cd aliases
  $ cat <<EOF >> .hg/hgrc
  > [templatealias]
  > r = rev
  > rn = "{r}:{node|short}"
  > status(c, files) = files % "{c} {file}\n"
  > utcdate(d) = localdate(d, "UTC")
  > EOF

  $ hg debugtemplate -vr0 '{rn} {utcdate(date)|isodate}\n'
  (template
    (symbol 'rn')
    (string ' ')
    (|
      (func
        (symbol 'utcdate')
        (symbol 'date'))
      (symbol 'isodate'))
    (string '\n'))
  * expanded:
  (template
    (template
      (symbol 'rev')
      (string ':')
      (|
        (symbol 'node')
        (symbol 'short')))
    (string ' ')
    (|
      (func
        (symbol 'localdate')
        (list
          (symbol 'date')
          (string 'UTC')))
      (symbol 'isodate'))
    (string '\n'))
  * keywords: date, node, rev
  * functions: isodate, localdate, short
  0:1e4e1b8f71e0 1970-01-12 13:46 +0000

  $ hg debugtemplate -vr0 '{status("A", file_adds)}'
  (template
    (func
      (symbol 'status')
      (list
        (string 'A')
        (symbol 'file_adds'))))
  * expanded:
  (template
    (%
      (symbol 'file_adds')
      (template
        (string 'A')
        (string ' ')
        (symbol 'file')
        (string '\n'))))
  * keywords: file, file_adds
  * functions: 
  A a

A unary function alias can be called as a filter:

  $ hg debugtemplate -vr0 '{date|utcdate|isodate}\n'
  (template
    (|
      (|
        (symbol 'date')
        (symbol 'utcdate'))
      (symbol 'isodate'))
    (string '\n'))
  * expanded:
  (template
    (|
      (func
        (symbol 'localdate')
        (list
          (symbol 'date')
          (string 'UTC')))
      (symbol 'isodate'))
    (string '\n'))
  * keywords: date
  * functions: isodate, localdate
  1970-01-12 13:46 +0000

Aliases should be applied only to command arguments and templates in hgrc.
Otherwise, our stock styles and web templates could be corrupted:

  $ hg log -r0 -T '{rn} {utcdate(date)|isodate}\n'
  0:1e4e1b8f71e0 1970-01-12 13:46 +0000

  $ hg log -r0 --config ui.logtemplate='"{rn} {utcdate(date)|isodate}\n"'
  0:1e4e1b8f71e0 1970-01-12 13:46 +0000

  $ cat <<EOF > tmpl
  > changeset = 'nothing expanded:{rn}\n'
  > EOF
  $ hg log -r0 --style ./tmpl
  nothing expanded:

Aliases in formatter:

  $ hg branches -T '{pad(branch, 7)} {rn}\n'
  default 6:d41e714fe50d
  foo     4:bbe44766e73d

Aliases should honor HGPLAIN:

  $ HGPLAIN= hg log -r0 -T 'nothing expanded:{rn}\n'
  nothing expanded:
  $ HGPLAINEXCEPT=templatealias hg log -r0 -T '{rn}\n'
  0:1e4e1b8f71e0

Unparsable alias:

  $ hg debugtemplate --config templatealias.bad='x(' -v '{bad}'
  (template
    (symbol 'bad'))
  abort: bad definition of template alias "bad": at 2: not a prefix: end
  [255]
  $ hg log --config templatealias.bad='x(' -T '{bad}'
  abort: bad definition of template alias "bad": at 2: not a prefix: end
  [255]

  $ cd ..

Test that template function in extension is registered as expected

  $ cd a

  $ cat <<EOF > $TESTTMP/customfunc.py
  > from mercurial import registrar
  > 
  > templatefunc = registrar.templatefunc()
  > 
  > @templatefunc(b'custom()')
  > def custom(context, mapping, args):
  >     return b'custom'
  > EOF
  $ cat <<EOF > .hg/hgrc
  > [extensions]
  > customfunc = $TESTTMP/customfunc.py
  > EOF

  $ hg log -r . -T "{custom()}\n" --config customfunc.enabled=true
  custom

  $ cd ..