templatefuncs: show hint if extdata source is evaluated to empty (issue5843)

mercurial/templatefuncs.py

@@ -1,696 +1,703 b''
 # templatefuncs.py - common template functions
 #
 # Copyright 2005, 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import re
 
 from .i18n import _
 from .node import (
     bin,
     wdirid,
 )
 from . import (
     color,
     encoding,
     error,
     minirst,
     obsutil,
     pycompat,
     registrar,
     revset as revsetmod,
     revsetlang,
     scmutil,
     templatefilters,
     templatekw,
     templateutil,
     util,
 )
 from .utils import (
     dateutil,
     stringutil,
 )
 
 evalrawexp = templateutil.evalrawexp
 evalfuncarg = templateutil.evalfuncarg
 evalboolean = templateutil.evalboolean
 evaldate = templateutil.evaldate
 evalinteger = templateutil.evalinteger
 evalstring = templateutil.evalstring
 evalstringliteral = templateutil.evalstringliteral
 
 # dict of template built-in functions
 funcs = {}
 templatefunc = registrar.templatefunc(funcs)
 
 @templatefunc('date(date[, fmt])')
 def date(context, mapping, args):
     """Format a date. See :hg:`help dates` for formatting
     strings. The default is a Unix date format, including the timezone:
     "Mon Sep 04 15:13:13 2006 0700"."""
     if not (1 <= len(args) <= 2):
         # i18n: "date" is a keyword
         raise error.ParseError(_("date expects one or two arguments"))
 
     date = evaldate(context, mapping, args[0],
                     # i18n: "date" is a keyword
                     _("date expects a date information"))
     fmt = None
     if len(args) == 2:
         fmt = evalstring(context, mapping, args[1])
     if fmt is None:
         return dateutil.datestr(date)
     else:
         return dateutil.datestr(date, fmt)
 
 @templatefunc('dict([[key=]value...])', argspec='*args **kwargs')
 def dict_(context, mapping, args):
     """Construct a dict from key-value pairs. A key may be omitted if
     a value expression can provide an unambiguous name."""
     data = util.sortdict()
 
     for v in args['args']:
         k = templateutil.findsymbolicname(v)
         if not k:
             raise error.ParseError(_('dict key cannot be inferred'))
         if k in data or k in args['kwargs']:
             raise error.ParseError(_("duplicated dict key '%s' inferred") % k)
         data[k] = evalfuncarg(context, mapping, v)
 
     data.update((k, evalfuncarg(context, mapping, v))
                 for k, v in args['kwargs'].iteritems())
     return templateutil.hybriddict(data)
 
 @templatefunc('diff([includepattern [, excludepattern]])')
 def diff(context, mapping, args):
     """Show a diff, optionally
     specifying files to include or exclude."""
     if len(args) > 2:
         # i18n: "diff" is a keyword
         raise error.ParseError(_("diff expects zero, one, or two arguments"))
 
     def getpatterns(i):
         if i < len(args):
             s = evalstring(context, mapping, args[i]).strip()
             if s:
                 return [s]
         return []
 
     ctx = context.resource(mapping, 'ctx')
     chunks = ctx.diff(match=ctx.match([], getpatterns(0), getpatterns(1)))
 
     return ''.join(chunks)
 
 @templatefunc('extdata(source)', argspec='source')
 def extdata(context, mapping, args):
     """Show a text read from the specified extdata source. (EXPERIMENTAL)"""
     if 'source' not in args:
         # i18n: "extdata" is a keyword
         raise error.ParseError(_('extdata expects one argument'))
 
     source = evalstring(context, mapping, args['source'])
+    if not source:
+        sym = templateutil.findsymbolicname(args['source'])
+        if sym:
+            raise error.ParseError(_('empty data source specified'),
+                                   hint=_("did you mean extdata('%s')?") % sym)
+        else:
+            raise error.ParseError(_('empty data source specified'))
     cache = context.resource(mapping, 'cache').setdefault('extdata', {})
     ctx = context.resource(mapping, 'ctx')
     if source in cache:
         data = cache[source]
     else:
         data = cache[source] = scmutil.extdatasource(ctx.repo(), source)
     return data.get(ctx.rev(), '')
 
 @templatefunc('files(pattern)')
 def files(context, mapping, args):
     """All files of the current changeset matching the pattern. See
     :hg:`help patterns`."""
     if not len(args) == 1:
         # i18n: "files" is a keyword
         raise error.ParseError(_("files expects one argument"))
 
     raw = evalstring(context, mapping, args[0])
     ctx = context.resource(mapping, 'ctx')
     m = ctx.match([raw])
     files = list(ctx.matches(m))
     return templateutil.compatlist(context, mapping, "file", files)
 
 @templatefunc('fill(text[, width[, initialident[, hangindent]]])')
 def fill(context, mapping, args):
     """Fill many
     paragraphs with optional indentation. See the "fill" filter."""
     if not (1 <= len(args) <= 4):
         # i18n: "fill" is a keyword
         raise error.ParseError(_("fill expects one to four arguments"))
 
     text = evalstring(context, mapping, args[0])
     width = 76
     initindent = ''
     hangindent = ''
     if 2 <= len(args) <= 4:
         width = evalinteger(context, mapping, args[1],
                             # i18n: "fill" is a keyword
                             _("fill expects an integer width"))
         try:
             initindent = evalstring(context, mapping, args[2])
             hangindent = evalstring(context, mapping, args[3])
         except IndexError:
             pass
 
     return templatefilters.fill(text, width, initindent, hangindent)
 
 @templatefunc('formatnode(node)')
 def formatnode(context, mapping, args):
     """Obtain the preferred form of a changeset hash. (DEPRECATED)"""
     if len(args) != 1:
         # i18n: "formatnode" is a keyword
         raise error.ParseError(_("formatnode expects one argument"))
 
     ui = context.resource(mapping, 'ui')
     node = evalstring(context, mapping, args[0])
     if ui.debugflag:
         return node
     return templatefilters.short(node)
 
 @templatefunc('mailmap(author)')
 def mailmap(context, mapping, args):
     """Return the author, updated according to the value
     set in the .mailmap file"""
     if len(args) != 1:
         raise error.ParseError(_("mailmap expects one argument"))
 
     author = evalstring(context, mapping, args[0])
 
     cache = context.resource(mapping, 'cache')
     repo = context.resource(mapping, 'repo')
 
     if 'mailmap' not in cache:
         data = repo.wvfs.tryread('.mailmap')
         cache['mailmap'] = stringutil.parsemailmap(data)
 
     return stringutil.mapname(cache['mailmap'], author)
 
 @templatefunc('pad(text, width[, fillchar=\' \'[, left=False]])',
               argspec='text width fillchar left')
 def pad(context, mapping, args):
     """Pad text with a
     fill character."""
     if 'text' not in args or 'width' not in args:
         # i18n: "pad" is a keyword
         raise error.ParseError(_("pad() expects two to four arguments"))
 
     width = evalinteger(context, mapping, args['width'],
                         # i18n: "pad" is a keyword
                         _("pad() expects an integer width"))
 
     text = evalstring(context, mapping, args['text'])
 
     left = False
     fillchar = ' '
     if 'fillchar' in args:
         fillchar = evalstring(context, mapping, args['fillchar'])
         if len(color.stripeffects(fillchar)) != 1:
             # i18n: "pad" is a keyword
             raise error.ParseError(_("pad() expects a single fill character"))
     if 'left' in args:
         left = evalboolean(context, mapping, args['left'])
 
     fillwidth = width - encoding.colwidth(color.stripeffects(text))
     if fillwidth <= 0:
         return text
     if left:
         return fillchar * fillwidth + text
     else:
         return text + fillchar * fillwidth
 
 @templatefunc('indent(text, indentchars[, firstline])')
 def indent(context, mapping, args):
     """Indents all non-empty lines
     with the characters given in the indentchars string. An optional
     third parameter will override the indent for the first line only
     if present."""
     if not (2 <= len(args) <= 3):
         # i18n: "indent" is a keyword
         raise error.ParseError(_("indent() expects two or three arguments"))
 
     text = evalstring(context, mapping, args[0])
     indent = evalstring(context, mapping, args[1])
 
     if len(args) == 3:
         firstline = evalstring(context, mapping, args[2])
     else:
         firstline = indent
 
     # the indent function doesn't indent the first line, so we do it here
     return templatefilters.indent(firstline + text, indent)
 
 @templatefunc('get(dict, key)')
 def get(context, mapping, args):
     """Get an attribute/key from an object. Some keywords
     are complex types. This function allows you to obtain the value of an
     attribute on these types."""
     if len(args) != 2:
         # i18n: "get" is a keyword
         raise error.ParseError(_("get() expects two arguments"))
 
     dictarg = evalfuncarg(context, mapping, args[0])
     if not util.safehasattr(dictarg, 'get'):
         # i18n: "get" is a keyword
         raise error.ParseError(_("get() expects a dict as first argument"))
 
     key = evalfuncarg(context, mapping, args[1])
     return templateutil.getdictitem(dictarg, key)
 
 @templatefunc('if(expr, then[, else])')
 def if_(context, mapping, args):
     """Conditionally execute based on the result of
     an expression."""
     if not (2 <= len(args) <= 3):
         # i18n: "if" is a keyword
         raise error.ParseError(_("if expects two or three arguments"))
 
     test = evalboolean(context, mapping, args[0])
     if test:
         return evalrawexp(context, mapping, args[1])
     elif len(args) == 3:
         return evalrawexp(context, mapping, args[2])
 
 @templatefunc('ifcontains(needle, haystack, then[, else])')
 def ifcontains(context, mapping, args):
     """Conditionally execute based
     on whether the item "needle" is in "haystack"."""
     if not (3 <= len(args) <= 4):
         # i18n: "ifcontains" is a keyword
         raise error.ParseError(_("ifcontains expects three or four arguments"))
 
     haystack = evalfuncarg(context, mapping, args[1])
     keytype = getattr(haystack, 'keytype', None)
     try:
         needle = evalrawexp(context, mapping, args[0])
         needle = templateutil.unwrapastype(context, mapping, needle,
                                            keytype or bytes)
         found = (needle in haystack)
     except error.ParseError:
         found = False
 
     if found:
         return evalrawexp(context, mapping, args[2])
     elif len(args) == 4:
         return evalrawexp(context, mapping, args[3])
 
 @templatefunc('ifeq(expr1, expr2, then[, else])')
 def ifeq(context, mapping, args):
     """Conditionally execute based on
     whether 2 items are equivalent."""
     if not (3 <= len(args) <= 4):
         # i18n: "ifeq" is a keyword
         raise error.ParseError(_("ifeq expects three or four arguments"))
 
     test = evalstring(context, mapping, args[0])
     match = evalstring(context, mapping, args[1])
     if test == match:
         return evalrawexp(context, mapping, args[2])
     elif len(args) == 4:
         return evalrawexp(context, mapping, args[3])
 
 @templatefunc('join(list, sep)')
 def join(context, mapping, args):
     """Join items in a list with a delimiter."""
     if not (1 <= len(args) <= 2):
         # i18n: "join" is a keyword
         raise error.ParseError(_("join expects one or two arguments"))
 
     joinset = evalrawexp(context, mapping, args[0])
     joiner = " "
     if len(args) > 1:
         joiner = evalstring(context, mapping, args[1])
     if isinstance(joinset, templateutil.wrapped):
         return joinset.join(context, mapping, joiner)
     # TODO: perhaps a generator should be stringify()-ed here, but we can't
     # because hgweb abuses it as a keyword that returns a list of dicts.
     joinset = templateutil.unwrapvalue(context, mapping, joinset)
     return templateutil.joinitems(pycompat.maybebytestr(joinset), joiner)
 
 @templatefunc('label(label, expr)')
 def label(context, mapping, args):
     """Apply a label to generated content. Content with
     a label applied can result in additional post-processing, such as
     automatic colorization."""
     if len(args) != 2:
         # i18n: "label" is a keyword
         raise error.ParseError(_("label expects two arguments"))
 
     ui = context.resource(mapping, 'ui')
     thing = evalstring(context, mapping, args[1])
     # preserve unknown symbol as literal so effects like 'red', 'bold',
     # etc. don't need to be quoted
     label = evalstringliteral(context, mapping, args[0])
 
     return ui.label(thing, label)
 
 @templatefunc('latesttag([pattern])')
 def latesttag(context, mapping, args):
     """The global tags matching the given pattern on the
     most recent globally tagged ancestor of this changeset.
     If no such tags exist, the "{tag}" template resolves to
     the string "null"."""
     if len(args) > 1:
         # i18n: "latesttag" is a keyword
         raise error.ParseError(_("latesttag expects at most one argument"))
 
     pattern = None
     if len(args) == 1:
         pattern = evalstring(context, mapping, args[0])
     return templatekw.showlatesttags(context, mapping, pattern)
 
 @templatefunc('localdate(date[, tz])')
 def localdate(context, mapping, args):
     """Converts a date to the specified timezone.
     The default is local date."""
     if not (1 <= len(args) <= 2):
         # i18n: "localdate" is a keyword
         raise error.ParseError(_("localdate expects one or two arguments"))
 
     date = evaldate(context, mapping, args[0],
                     # i18n: "localdate" is a keyword
                     _("localdate expects a date information"))
     if len(args) >= 2:
         tzoffset = None
         tz = evalfuncarg(context, mapping, args[1])
         if isinstance(tz, bytes):
             tzoffset, remainder = dateutil.parsetimezone(tz)
             if remainder:
                 tzoffset = None
         if tzoffset is None:
             try:
                 tzoffset = int(tz)
             except (TypeError, ValueError):
                 # i18n: "localdate" is a keyword
                 raise error.ParseError(_("localdate expects a timezone"))
     else:
         tzoffset = dateutil.makedate()[1]
     return (date[0], tzoffset)
 
 @templatefunc('max(iterable)')
 def max_(context, mapping, args, **kwargs):
     """Return the max of an iterable"""
     if len(args) != 1:
         # i18n: "max" is a keyword
         raise error.ParseError(_("max expects one argument"))
 
     iterable = evalfuncarg(context, mapping, args[0])
     try:
         x = max(pycompat.maybebytestr(iterable))
     except (TypeError, ValueError):
         # i18n: "max" is a keyword
         raise error.ParseError(_("max first argument should be an iterable"))
     return templateutil.wraphybridvalue(iterable, x, x)
 
 @templatefunc('min(iterable)')
 def min_(context, mapping, args, **kwargs):
     """Return the min of an iterable"""
     if len(args) != 1:
         # i18n: "min" is a keyword
         raise error.ParseError(_("min expects one argument"))
 
     iterable = evalfuncarg(context, mapping, args[0])
     try:
         x = min(pycompat.maybebytestr(iterable))
     except (TypeError, ValueError):
         # i18n: "min" is a keyword
         raise error.ParseError(_("min first argument should be an iterable"))
     return templateutil.wraphybridvalue(iterable, x, x)
 
 @templatefunc('mod(a, b)')
 def mod(context, mapping, args):
     """Calculate a mod b such that a / b + a mod b == a"""
     if not len(args) == 2:
         # i18n: "mod" is a keyword
         raise error.ParseError(_("mod expects two arguments"))
 
     func = lambda a, b: a % b
     return templateutil.runarithmetic(context, mapping,
                                       (func, args[0], args[1]))
 
 @templatefunc('obsfateoperations(markers)')
 def obsfateoperations(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfateoperations" is a keyword
         raise error.ParseError(_("obsfateoperations expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersoperations(markers)
         return templateutil.hybridlist(data, name='operation')
     except (TypeError, KeyError):
         # i18n: "obsfateoperations" is a keyword
         errmsg = _("obsfateoperations first argument should be an iterable")
         raise error.ParseError(errmsg)
 
 @templatefunc('obsfatedate(markers)')
 def obsfatedate(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfatedate" is a keyword
         raise error.ParseError(_("obsfatedate expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersdates(markers)
         return templateutil.hybridlist(data, name='date', fmt='%d %d')
     except (TypeError, KeyError):
         # i18n: "obsfatedate" is a keyword
         errmsg = _("obsfatedate first argument should be an iterable")
         raise error.ParseError(errmsg)
 
 @templatefunc('obsfateusers(markers)')
 def obsfateusers(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfateusers" is a keyword
         raise error.ParseError(_("obsfateusers expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersusers(markers)
         return templateutil.hybridlist(data, name='user')
     except (TypeError, KeyError, ValueError):
         # i18n: "obsfateusers" is a keyword
         msg = _("obsfateusers first argument should be an iterable of "
                 "obsmakers")
         raise error.ParseError(msg)
 
 @templatefunc('obsfateverb(successors, markers)')
 def obsfateverb(context, mapping, args):
     """Compute obsfate related information based on successors (EXPERIMENTAL)"""
     if len(args) != 2:
         # i18n: "obsfateverb" is a keyword
         raise error.ParseError(_("obsfateverb expects two arguments"))
 
     successors = evalfuncarg(context, mapping, args[0])
     markers = evalfuncarg(context, mapping, args[1])
 
     try:
         return obsutil.obsfateverb(successors, markers)
     except TypeError:
         # i18n: "obsfateverb" is a keyword
         errmsg = _("obsfateverb first argument should be countable")
         raise error.ParseError(errmsg)
 
 @templatefunc('relpath(path)')
 def relpath(context, mapping, args):
     """Convert a repository-absolute path into a filesystem path relative to
     the current working directory."""
     if len(args) != 1:
         # i18n: "relpath" is a keyword
         raise error.ParseError(_("relpath expects one argument"))
 
     repo = context.resource(mapping, 'ctx').repo()
     path = evalstring(context, mapping, args[0])
     return repo.pathto(path)
 
 @templatefunc('revset(query[, formatargs...])')
 def revset(context, mapping, args):
     """Execute a revision set query. See
     :hg:`help revset`."""
     if not len(args) > 0:
         # i18n: "revset" is a keyword
         raise error.ParseError(_("revset expects one or more arguments"))
 
     raw = evalstring(context, mapping, args[0])
     ctx = context.resource(mapping, 'ctx')
     repo = ctx.repo()
 
     def query(expr):
         m = revsetmod.match(repo.ui, expr, lookup=revsetmod.lookupfn(repo))
         return m(repo)
 
     if len(args) > 1:
         formatargs = [evalfuncarg(context, mapping, a) for a in args[1:]]
         revs = query(revsetlang.formatspec(raw, *formatargs))
         revs = list(revs)
     else:
         cache = context.resource(mapping, 'cache')
         revsetcache = cache.setdefault("revsetcache", {})
         if raw in revsetcache:
             revs = revsetcache[raw]
         else:
             revs = query(raw)
             revs = list(revs)
             revsetcache[raw] = revs
     return templatekw.showrevslist(context, mapping, "revision", revs)
 
 @templatefunc('rstdoc(text, style)')
 def rstdoc(context, mapping, args):
     """Format reStructuredText."""
     if len(args) != 2:
         # i18n: "rstdoc" is a keyword
         raise error.ParseError(_("rstdoc expects two arguments"))
 
     text = evalstring(context, mapping, args[0])
     style = evalstring(context, mapping, args[1])
 
     return minirst.format(text, style=style, keep=['verbose'])
 
 @templatefunc('separate(sep, args)', argspec='sep *args')
 def separate(context, mapping, args):
     """Add a separator between non-empty arguments."""
     if 'sep' not in args:
         # i18n: "separate" is a keyword
         raise error.ParseError(_("separate expects at least one argument"))
 
     sep = evalstring(context, mapping, args['sep'])
     first = True
     for arg in args['args']:
         argstr = evalstring(context, mapping, arg)
         if not argstr:
             continue
         if first:
             first = False
         else:
             yield sep
         yield argstr
 
 @templatefunc('shortest(node, minlength=4)')
 def shortest(context, mapping, args):
     """Obtain the shortest representation of
     a node."""
     if not (1 <= len(args) <= 2):
         # i18n: "shortest" is a keyword
         raise error.ParseError(_("shortest() expects one or two arguments"))
 
     hexnode = evalstring(context, mapping, args[0])
 
     minlength = 4
     if len(args) > 1:
         minlength = evalinteger(context, mapping, args[1],
                                 # i18n: "shortest" is a keyword
                                 _("shortest() expects an integer minlength"))
 
     repo = context.resource(mapping, 'ctx')._repo
     if len(hexnode) > 40:
         return hexnode
     elif len(hexnode) == 40:
         try:
             node = bin(hexnode)
         except TypeError:
             return hexnode
     else:
         try:
             node = scmutil.resolvehexnodeidprefix(repo, hexnode)
         except error.WdirUnsupported:
             node = wdirid
         except error.LookupError:
             return hexnode
         if not node:
             return hexnode
     try:
         return scmutil.shortesthexnodeidprefix(repo, node, minlength)
     except error.RepoLookupError:
         return hexnode
 
 @templatefunc('strip(text[, chars])')
 def strip(context, mapping, args):
     """Strip characters from a string. By default,
     strips all leading and trailing whitespace."""
     if not (1 <= len(args) <= 2):
         # i18n: "strip" is a keyword
         raise error.ParseError(_("strip expects one or two arguments"))
 
     text = evalstring(context, mapping, args[0])
     if len(args) == 2:
         chars = evalstring(context, mapping, args[1])
         return text.strip(chars)
     return text.strip()
 
 @templatefunc('sub(pattern, replacement, expression)')
 def sub(context, mapping, args):
     """Perform text substitution
     using regular expressions."""
     if len(args) != 3:
         # i18n: "sub" is a keyword
         raise error.ParseError(_("sub expects three arguments"))
 
     pat = evalstring(context, mapping, args[0])
     rpl = evalstring(context, mapping, args[1])
     src = evalstring(context, mapping, args[2])
     try:
         patre = re.compile(pat)
     except re.error:
         # i18n: "sub" is a keyword
         raise error.ParseError(_("sub got an invalid pattern: %s") % pat)
     try:
         yield patre.sub(rpl, src)
     except re.error:
         # i18n: "sub" is a keyword
         raise error.ParseError(_("sub got an invalid replacement: %s") % rpl)
 
 @templatefunc('startswith(pattern, text)')
 def startswith(context, mapping, args):
     """Returns the value from the "text" argument
     if it begins with the content from the "pattern" argument."""
     if len(args) != 2:
         # i18n: "startswith" is a keyword
         raise error.ParseError(_("startswith expects two arguments"))
 
     patn = evalstring(context, mapping, args[0])
     text = evalstring(context, mapping, args[1])
     if text.startswith(patn):
         return text
     return ''
 
 @templatefunc('word(number, text[, separator])')
 def word(context, mapping, args):
     """Return the nth word from a string."""
     if not (2 <= len(args) <= 3):
         # i18n: "word" is a keyword
         raise error.ParseError(_("word expects two or three arguments, got %d")
                                % len(args))
 
     num = evalinteger(context, mapping, args[0],
                       # i18n: "word" is a keyword
                       _("word expects an integer index"))
     text = evalstring(context, mapping, args[1])
     if len(args) == 3:
         splitter = evalstring(context, mapping, args[2])
     else:
         splitter = None
 
     tokens = text.split(splitter)
     if num >= len(tokens) or num < -len(tokens):
         return ''
     else:
         return tokens[num]
 
 def loadfunction(ui, extname, registrarobj):
     """Load template function from specified registrarobj
     """
     for name, func in registrarobj._table.iteritems():
         funcs[name] = func
 
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = funcs.values()

tests/test-extdata.t

@@ -1,96 +1,103 b''
   $ hg init repo
   $ cd repo
   $ for n in 0 1 2 3 4 5 6 7 8 9 10 11; do
   >   echo $n > $n
   >   hg ci -qAm $n
   > done
 
 test revset support
 
   $ cat <<'EOF' >> .hg/hgrc
   > [extdata]
   > filedata = file:extdata.txt
   > notes = notes.txt
   > shelldata = shell:cat extdata.txt | grep 2
   > emptygrep = shell:cat extdata.txt | grep empty
   > EOF
   $ cat <<'EOF' > extdata.txt
   > 2 another comment on 2
   > 3
   > EOF
   $ cat <<'EOF' > notes.txt
   > f6ed this change is great!
   > e834 this is buggy :(
   > 0625 first post
   > bogusnode gives no error
   > a ambiguous node gives no error
   > EOF
 
   $ hg log -qr "extdata(filedata)"
   2:f6ed99a58333
   3:9de260b1e88e
   $ hg log -qr "extdata(shelldata)"
   2:f6ed99a58333
 
 test weight of extdata() revset
 
   $ hg debugrevspec -p optimized "extdata(filedata) & 3"
   * optimized:
   (andsmally
     (func
       (symbol 'extdata')
       (symbol 'filedata'))
     (symbol '3'))
   3
 
 test non-zero exit of shell command
 
   $ hg log -qr "extdata(emptygrep)"
   abort: extdata command 'cat extdata.txt | grep empty' failed: exited with status 1
   [255]
 
 test bad extdata() revset source
 
   $ hg log -qr "extdata()"
   hg: parse error: extdata takes at least 1 string argument
   [255]
   $ hg log -qr "extdata(unknown)"
   abort: unknown extdata source 'unknown'
   [255]
 
 test template support:
 
   $ hg log -r:3 -T "{node|short}{if(extdata('notes'), ' # {extdata('notes')}')}\n"
   06254b906311 # first post
   e8342c9a2ed1 # this is buggy :(
   f6ed99a58333 # this change is great!
   9de260b1e88e
 
 test template cache:
 
   $ hg log -r:3 -T '{rev} "{extdata("notes")}" "{extdata("shelldata")}"\n'
   0 "first post" ""
   1 "this is buggy :(" ""
   2 "this change is great!" "another comment on 2"
   3 "" ""
 
 test bad extdata() template source
 
   $ hg log -T "{extdata()}\n"
   hg: parse error: extdata expects one argument
   [255]
   $ hg log -T "{extdata('unknown')}\n"
   abort: unknown extdata source 'unknown'
   [255]
+  $ hg log -T "{extdata(unknown)}\n"
+  hg: parse error: empty data source specified
+  (did you mean extdata('unknown')?)
+  [255]
+  $ hg log -T "{extdata('{unknown}')}\n"
+  hg: parse error: empty data source specified
+  [255]
 
 we don't fix up relative file URLs, but we do run shell commands in repo root
 
   $ mkdir sub
   $ cd sub
   $ hg log -qr "extdata(filedata)"
   abort: error: $ENOENT$
   [255]
   $ hg log -qr "extdata(shelldata)"
   2:f6ed99a58333
 
   $ cd ..