extensions: raise when trying to find an extension that failed to load

extensions that depend on other extensions (such as record) use this pattern
to check if the dependant extension is available:

    try:
        mq = extensions.find('mq')
    except KeyError:
        return

but since if an error occurs while loading an extension it leaves its entry
in the _extensions map as None, we want to raise in that situation too.

(rather than adding another check if the return value is None)

mercurial/extensions.py

@@ -1,334 +1,338 b''
 # extensions.py - extension handling for mercurial
 #
 # Copyright 2005-2007 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.
 
 import imp, os
 import util, cmdutil, error
 from i18n import _, gettext
 
 _extensions = {}
 _order = []
 _ignore = ['hbisect', 'bookmarks', 'parentrevspec']
 
 def extensions():
     for name in _order:
         module = _extensions[name]
         if module:
             yield name, module
 
 def find(name):
     '''return module with given extension name'''
+    mod = None
     try:
-        return _extensions[name]
+        mod =  _extensions[name]
     except KeyError:
         for k, v in _extensions.iteritems():
             if k.endswith('.' + name) or k.endswith('/' + name):
-                return v
+                mod = v
+                break
+    if not mod:
         raise KeyError(name)
+    return mod
 
 def loadpath(path, module_name):
     module_name = module_name.replace('.', '_')
     path = util.expandpath(path)
     if os.path.isdir(path):
         # module/__init__.py style
         d, f = os.path.split(path.rstrip('/'))
         fd, fpath, desc = imp.find_module(f, [d])
         return imp.load_module(module_name, fd, fpath, desc)
     else:
         return imp.load_source(module_name, path)
 
 def load(ui, name, path):
     # unused ui argument kept for backwards compatibility
     if name.startswith('hgext.') or name.startswith('hgext/'):
         shortname = name[6:]
     else:
         shortname = name
     if shortname in _ignore:
         return None
     if shortname in _extensions:
         return _extensions[shortname]
     _extensions[shortname] = None
     if path:
         # the module will be loaded in sys.modules
         # choose an unique name so that it doesn't
         # conflicts with other modules
         mod = loadpath(path, 'hgext.%s' % name)
     else:
         def importh(name):
             mod = __import__(name)
             components = name.split('.')
             for comp in components[1:]:
                 mod = getattr(mod, comp)
             return mod
         try:
             mod = importh("hgext.%s" % name)
         except ImportError:
             mod = importh(name)
     _extensions[shortname] = mod
     _order.append(shortname)
     return mod
 
 def loadall(ui):
     result = ui.configitems("extensions")
     newindex = len(_order)
     for (name, path) in result:
         if path:
             if path[0] == '!':
                 continue
         try:
             load(ui, name, path)
         except KeyboardInterrupt:
             raise
         except Exception, inst:
             if path:
                 ui.warn(_("*** failed to import extension %s from %s: %s\n")
                         % (name, path, inst))
             else:
                 ui.warn(_("*** failed to import extension %s: %s\n")
                         % (name, inst))
             if ui.traceback():
                 return 1
 
     for name in _order[newindex:]:
         uisetup = getattr(_extensions[name], 'uisetup', None)
         if uisetup:
             uisetup(ui)
 
     for name in _order[newindex:]:
         extsetup = getattr(_extensions[name], 'extsetup', None)
         if extsetup:
             try:
                 extsetup(ui)
             except TypeError:
                 if extsetup.func_code.co_argcount != 0:
                     raise
                 extsetup() # old extsetup with no ui argument
 
 def wrapcommand(table, command, wrapper):
     '''Wrap the command named `command' in table
 
     Replace command in the command table with wrapper. The wrapped command will
     be inserted into the command table specified by the table argument.
 
     The wrapper will be called like
 
       wrapper(orig, *args, **kwargs)
 
     where orig is the original (wrapped) function, and *args, **kwargs
     are the arguments passed to it.
     '''
     assert hasattr(wrapper, '__call__')
     aliases, entry = cmdutil.findcmd(command, table)
     for alias, e in table.iteritems():
         if e is entry:
             key = alias
             break
 
     origfn = entry[0]
     def wrap(*args, **kwargs):
         return util.checksignature(wrapper)(
             util.checksignature(origfn), *args, **kwargs)
 
     wrap.__doc__ = getattr(origfn, '__doc__')
     wrap.__module__ = getattr(origfn, '__module__')
 
     newentry = list(entry)
     newentry[0] = wrap
     table[key] = tuple(newentry)
     return entry
 
 def wrapfunction(container, funcname, wrapper):
     '''Wrap the function named funcname in container
 
     Replace the funcname member in the given container with the specified
     wrapper. The container is typically a module, class, or instance.
 
     The wrapper will be called like
 
       wrapper(orig, *args, **kwargs)
 
     where orig is the original (wrapped) function, and *args, **kwargs
     are the arguments passed to it.
 
     Wrapping methods of the repository object is not recommended since
     it conflicts with extensions that extend the repository by
     subclassing. All extensions that need to extend methods of
     localrepository should use this subclassing trick: namely,
     reposetup() should look like
 
       def reposetup(ui, repo):
           class myrepo(repo.__class__):
               def whatever(self, *args, **kwargs):
                   [...extension stuff...]
                   super(myrepo, self).whatever(*args, **kwargs)
                   [...extension stuff...]
 
           repo.__class__ = myrepo
 
     In general, combining wrapfunction() with subclassing does not
     work. Since you cannot control what other extensions are loaded by
     your end users, you should play nicely with others by using the
     subclass trick.
     '''
     assert hasattr(wrapper, '__call__')
     def wrap(*args, **kwargs):
         return wrapper(origfn, *args, **kwargs)
 
     origfn = getattr(container, funcname)
     assert hasattr(origfn, '__call__')
     setattr(container, funcname, wrap)
     return origfn
 
 def _disabledpaths(strip_init=False):
     '''find paths of disabled extensions. returns a dict of {name: path}
     removes /__init__.py from packages if strip_init is True'''
     import hgext
     extpath = os.path.dirname(os.path.abspath(hgext.__file__))
     try: # might not be a filesystem path
         files = os.listdir(extpath)
     except OSError:
         return {}
 
     exts = {}
     for e in files:
         if e.endswith('.py'):
             name = e.rsplit('.', 1)[0]
             path = os.path.join(extpath, e)
         else:
             name = e
             path = os.path.join(extpath, e, '__init__.py')
             if not os.path.exists(path):
                 continue
             if strip_init:
                 path = os.path.dirname(path)
         if name in exts or name in _order or name == '__init__':
             continue
         exts[name] = path
     return exts
 
 def _moduledoc(file):
     '''return the top-level python documentation for the given file
 
     Loosely inspired by pydoc.source_synopsis(), but rewritten to
     handle triple quotes and to return the whole text instead of just
     the synopsis'''
     result = []
 
     line = file.readline()
     while line[:1] == '#' or not line.strip():
         line = file.readline()
         if not line:
             break
 
     start = line[:3]
     if start == '"""' or start == "'''":
         line = line[3:]
         while line:
             if line.rstrip().endswith(start):
                 line = line.split(start)[0]
                 if line:
                     result.append(line)
                 break
             elif not line:
                 return None # unmatched delimiter
             result.append(line)
             line = file.readline()
     else:
         return None
 
     return ''.join(result)
 
 def _disabledhelp(path):
     '''retrieve help synopsis of a disabled extension (without importing)'''
     try:
         file = open(path)
     except IOError:
         return
     else:
         doc = _moduledoc(file)
         file.close()
 
     if doc: # extracting localized synopsis
         return gettext(doc).splitlines()[0]
     else:
         return _('(no help text available)')
 
 def disabled():
     '''find disabled extensions from hgext
     returns a dict of {name: desc}, and the max name length'''
 
     paths = _disabledpaths()
     if not paths:
         return None
 
     exts = {}
     for name, path in paths.iteritems():
         doc = _disabledhelp(path)
         if doc:
             exts[name] = doc
 
     return exts
 
 def disabledext(name):
     '''find a specific disabled extension from hgext. returns desc'''
     paths = _disabledpaths()
     if name in paths:
         return _disabledhelp(paths[name])
 
 def disabledcmd(ui, cmd, strict=False):
     '''import disabled extensions until cmd is found.
     returns (cmdname, extname, doc)'''
 
     paths = _disabledpaths(strip_init=True)
     if not paths:
         raise error.UnknownCommand(cmd)
 
     def findcmd(cmd, name, path):
         try:
             mod = loadpath(path, 'hgext.%s' % name)
         except Exception:
             return
         try:
             aliases, entry = cmdutil.findcmd(cmd,
                 getattr(mod, 'cmdtable', {}), strict)
         except (error.AmbiguousCommand, error.UnknownCommand):
             return
         except Exception:
             ui.warn(_('warning: error finding commands in %s\n') % path)
             ui.traceback()
             return
         for c in aliases:
             if c.startswith(cmd):
                 cmd = c
                 break
         else:
             cmd = aliases[0]
         return (cmd, name, mod)
 
     # first, search for an extension with the same name as the command
     path = paths.pop(cmd, None)
     if path:
         ext = findcmd(cmd, cmd, path)
         if ext:
             return ext
 
     # otherwise, interrogate each extension until there's a match
     for name, path in paths.iteritems():
         ext = findcmd(cmd, name, path)
         if ext:
             return ext
 
     raise error.UnknownCommand(cmd)
 
 def enabled():
     '''return a dict of {name: desc} of extensions, and the max name length'''
     exts = {}
     for ename, ext in extensions():
         doc = (gettext(ext.__doc__) or _('(no help text available)'))
         ename = ename.split('.')[-1]
         exts[ename] = doc.splitlines()[0].strip()
 
     return exts

tests/test-qrecord.t

@@ -1,368 +1,383 b''
 Create configuration
 
   $ echo "[ui]" >> $HGRCPATH
   $ echo "interactive=true" >> $HGRCPATH
 
 help record (no record)
 
   $ hg help record
   record extension - commands to interactively select changes for commit/qrefresh
   
   use "hg help extensions" for information on enabling extensions
 
 help qrecord (no record)
 
   $ hg help qrecord
   'qrecord' is provided by the following extension:
   
       record  commands to interactively select changes for commit/qrefresh
   
   use "hg help extensions" for information on enabling extensions
 
   $ echo "[extensions]"     >> $HGRCPATH
   $ echo "record="          >> $HGRCPATH
 
 help record (record)
 
   $ hg help record
   hg record [OPTION]... [FILE]...
   
   interactively select changes to commit
   
       If a list of files is omitted, all changes reported by "hg status" will be
       candidates for recording.
   
       See "hg help dates" for a list of formats valid for -d/--date.
   
       You will be prompted for whether to record changes to each modified file,
       and for files with multiple changes, for each change to use. For each
       query, the following responses are possible:
   
         y - record this change
         n - skip this change
   
         s - skip remaining changes to this file
         f - record remaining changes to this file
   
         d - done, skip remaining changes and files
         a - record all changes to all remaining files
         q - quit, recording no changes
   
         ? - display help
   
       This command is not available when committing a merge.
   
   options:
   
    -A --addremove            mark new/missing files as added/removed before
                              committing
       --close-branch         mark a branch as closed, hiding it from the branch
                              list
    -I --include PATTERN [+]  include names matching the given patterns
    -X --exclude PATTERN [+]  exclude names matching the given patterns
    -m --message TEXT         use text as commit message
    -l --logfile FILE         read commit message from file
    -d --date DATE            record the specified date as commit date
    -u --user USER            record the specified user as committer
   
   [+] marked option can be specified multiple times
   
   use "hg -v help record" to show global options
 
 help (no mq, so no qrecord)
 
   $ hg help qrecord
   hg qrecord [OPTION]... PATCH [FILE]...
   
   interactively record a new patch
   
       See "hg help qnew" & "hg help record" for more information and usage.
   
   use "hg -v help qrecord" to show global options
 
   $ hg init a
 
 qrecord (mq not present)
 
   $ hg -R a qrecord
   hg qrecord: invalid arguments
   hg qrecord [OPTION]... PATCH [FILE]...
   
   interactively record a new patch
   
   use "hg help qrecord" to show the full help text
   [255]
 
 qrecord patch (mq not present)
 
   $ hg -R a qrecord patch
   abort: 'mq' extension not loaded
   [255]
 
+help (bad mq)
+
+  $ echo "mq=nonexistant" >> $HGRCPATH
+  $ hg help qrecord
+  *** failed to import extension mq from nonexistant: [Errno 2] No such file or directory
+  hg qrecord [OPTION]... PATCH [FILE]...
+  
+  interactively record a new patch
+  
+      See "hg help qnew" & "hg help record" for more information and usage.
+  
+  use "hg -v help qrecord" to show global options
+
 help (mq present)
 
-  $ echo "mq="              >> $HGRCPATH
+  $ sed 's/mq=nonexistant/mq=/' $HGRCPATH > hgrc.tmp
+  $ mv hgrc.tmp $HGRCPATH
+
   $ hg help qrecord
   hg qrecord [OPTION]... PATCH [FILE]...
   
   interactively record a new patch
   
       See "hg help qnew" & "hg help record" for more information and usage.
   
   options:
   
    -e --edit                 edit commit message
    -g --git                  use git extended diff format
    -U --currentuser          add "From: <current user>" to patch
    -u --user USER            add "From: <USER>" to patch
    -D --currentdate          add "Date: <current date>" to patch
    -d --date DATE            add "Date: <DATE>" to patch
    -I --include PATTERN [+]  include names matching the given patterns
    -X --exclude PATTERN [+]  exclude names matching the given patterns
    -m --message TEXT         use text as commit message
    -l --logfile FILE         read commit message from file
   
   [+] marked option can be specified multiple times
   
   use "hg -v help qrecord" to show global options
 
   $ cd a
 
 Base commit
 
   $ cat > 1.txt <<EOF
   > 1
   > 2
   > 3
   > 4
   > 5
   > EOF
   $ cat > 2.txt <<EOF
   > a
   > b
   > c
   > d
   > e
   > f
   > EOF
 
   $ mkdir dir
   $ cat > dir/a.txt <<EOF
   > hello world
   > 
   > someone
   > up
   > there
   > loves
   > me
   > EOF
 
   $ hg add 1.txt 2.txt dir/a.txt
   $ hg commit -m 'initial checkin'
 
 Changing files
 
   $ sed -e 's/2/2 2/;s/4/4 4/' 1.txt > 1.txt.new
   $ sed -e 's/b/b b/' 2.txt > 2.txt.new
   $ sed -e 's/hello world/hello world!/' dir/a.txt > dir/a.txt.new
 
   $ mv -f 1.txt.new 1.txt
   $ mv -f 2.txt.new 2.txt
   $ mv -f dir/a.txt.new dir/a.txt
 
 Whole diff
 
   $ hg diff --nodates
   diff -r 1057167b20ef 1.txt
   --- a/1.txt
   +++ b/1.txt
   @@ -1,5 +1,5 @@
    1
   -2
   +2 2
    3
   -4
   +4 4
    5
   diff -r 1057167b20ef 2.txt
   --- a/2.txt
   +++ b/2.txt
   @@ -1,5 +1,5 @@
    a
   -b
   +b b
    c
    d
    e
   diff -r 1057167b20ef dir/a.txt
   --- a/dir/a.txt
   +++ b/dir/a.txt
   @@ -1,4 +1,4 @@
   -hello world
   +hello world!
    
    someone
    up
 
 qrecord a.patch
 
   $ hg qrecord -d '0 0' -m aaa a.patch <<EOF
   > y
   > y
   > n
   > y
   > y
   > n
   > EOF
   diff --git a/1.txt b/1.txt
   2 hunks, 2 lines changed
   examine changes to '1.txt'? [Ynsfdaq?] 
   @@ -1,3 +1,3 @@
    1
   -2
   +2 2
    3
   record change 1/4 to '1.txt'? [Ynsfdaq?] 
   @@ -3,3 +3,3 @@
    3
   -4
   +4 4
    5
   record change 2/4 to '1.txt'? [Ynsfdaq?] 
   diff --git a/2.txt b/2.txt
   1 hunks, 1 lines changed
   examine changes to '2.txt'? [Ynsfdaq?] 
   @@ -1,5 +1,5 @@
    a
   -b
   +b b
    c
    d
    e
   record change 3/4 to '2.txt'? [Ynsfdaq?] 
   diff --git a/dir/a.txt b/dir/a.txt
   1 hunks, 1 lines changed
   examine changes to 'dir/a.txt'? [Ynsfdaq?] 
 
 After qrecord a.patch 'tip'"
 
   $ hg tip -p
   changeset:   1:5d1ca63427ee
   tag:         a.patch
   tag:         qbase
   tag:         qtip
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     aaa
   
   diff -r 1057167b20ef -r 5d1ca63427ee 1.txt
   --- a/1.txt	Thu Jan 01 00:00:00 1970 +0000
   +++ b/1.txt	Thu Jan 01 00:00:00 1970 +0000
   @@ -1,5 +1,5 @@
    1
   -2
   +2 2
    3
    4
    5
   diff -r 1057167b20ef -r 5d1ca63427ee 2.txt
   --- a/2.txt	Thu Jan 01 00:00:00 1970 +0000
   +++ b/2.txt	Thu Jan 01 00:00:00 1970 +0000
   @@ -1,5 +1,5 @@
    a
   -b
   +b b
    c
    d
    e
   
 
 After qrecord a.patch 'diff'"
 
   $ hg diff --nodates
   diff -r 5d1ca63427ee 1.txt
   --- a/1.txt
   +++ b/1.txt
   @@ -1,5 +1,5 @@
    1
    2 2
    3
   -4
   +4 4
    5
   diff -r 5d1ca63427ee dir/a.txt
   --- a/dir/a.txt
   +++ b/dir/a.txt
   @@ -1,4 +1,4 @@
   -hello world
   +hello world!
    
    someone
    up
 
 qrecord b.patch
 
   $ hg qrecord -d '0 0' -m bbb b.patch <<EOF
   > y
   > y
   > y
   > y
   > EOF
   diff --git a/1.txt b/1.txt
   1 hunks, 1 lines changed
   examine changes to '1.txt'? [Ynsfdaq?] 
   @@ -1,5 +1,5 @@
    1
    2 2
    3
   -4
   +4 4
    5
   record change 1/2 to '1.txt'? [Ynsfdaq?] 
   diff --git a/dir/a.txt b/dir/a.txt
   1 hunks, 1 lines changed
   examine changes to 'dir/a.txt'? [Ynsfdaq?] 
   @@ -1,4 +1,4 @@
   -hello world
   +hello world!
    
    someone
    up
   record change 2/2 to 'dir/a.txt'? [Ynsfdaq?] 
 
 After qrecord b.patch 'tip'
 
   $ hg tip -p
   changeset:   2:b056198bf878
   tag:         b.patch
   tag:         qtip
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     bbb
   
   diff -r 5d1ca63427ee -r b056198bf878 1.txt
   --- a/1.txt	Thu Jan 01 00:00:00 1970 +0000
   +++ b/1.txt	Thu Jan 01 00:00:00 1970 +0000
   @@ -1,5 +1,5 @@
    1
    2 2
    3
   -4
   +4 4
    5
   diff -r 5d1ca63427ee -r b056198bf878 dir/a.txt
   --- a/dir/a.txt	Thu Jan 01 00:00:00 1970 +0000
   +++ b/dir/a.txt	Thu Jan 01 00:00:00 1970 +0000
   @@ -1,4 +1,4 @@
   -hello world
   +hello world!
    
    someone
    up
   
 
 After qrecord b.patch 'diff'
 
   $ hg diff --nodates