convert: use None value for missing files instead of overloading IOError

The internal API used IOError to indicate that a file should be marked as
removed.

There is some correlation between IOError (especially with ENOENT) and files
that should be removed, but using IOErrors to represent file removal internally
required some hacks.

Instead, use the value None to indicate that the file not is present.

Before, spurious IO errors could cause commits that silently removed files.
They will now be reported like all other IO errors so the root cause can be
fixed.

hgext/convert/bzr.py

@@ -122,8 +122,7 b' class bzr_source(converter_source):'
             kind = revtree.kind(fileid)
         if kind not in supportedkinds:
             # the file is not available anymore - was deleted
-            raise IOError(_('%s is not available in %s anymore') %
-                    (name, rev))
+            return None, None
         mode = self._modecache[(name, rev)]
         if kind == 'symlink':
             target = revtree.get_symlink_target(fileid)

hgext/convert/common.py

@@ -88,8 +88,8 b' class converter_source(object):'
     def getfile(self, name, rev):
         """Return a pair (data, mode) where data is the file content
         as a string and mode one of '', 'x' or 'l'. rev is the
-        identifier returned by a previous call to getchanges(). Raise
-        IOError to indicate that name was deleted in rev.
+        identifier returned by a previous call to getchanges().
+        Data is None if file is missing/deleted in rev.
         """
         raise NotImplementedError
 

hgext/convert/cvs.py

@@ -220,7 +220,7 b' class convert_cvs(converter_source):'
 
         self._parse()
         if rev.endswith("(DEAD)"):
-            raise IOError
+            return None, None
 
         args = ("-N -P -kk -r %s --" % rev).split()
         args.append(self.cvsrepo + '/' + name)

hgext/convert/darcs.py

@@ -8,7 +8,7 b''
 from common import NoRepo, checktool, commandline, commit, converter_source
 from mercurial.i18n import _
 from mercurial import util
-import os, shutil, tempfile, re
+import os, shutil, tempfile, re, errno
 
 # The naming drift of ElementTree is fun!
 
@@ -192,8 +192,13 b' class darcs_source(converter_source, com'
         if rev != self.lastrev:
             raise util.Abort(_('internal calling inconsistency'))
         path = os.path.join(self.tmppath, name)
-        data = util.readfile(path)
-        mode = os.lstat(path).st_mode
+        try:
+            data = util.readfile(path)
+            mode = os.lstat(path).st_mode
+        except IOError, inst:
+            if inst.errno == errno.ENOENT:
+                return None, None
+            raise
         mode = (mode & 0111) and 'x' or ''
         return data, mode
 

hgext/convert/git.py

@@ -135,7 +135,7 b' class convert_git(converter_source):'
 
     def getfile(self, name, rev):
         if rev == hex(nullid):
-            raise IOError
+            return None, None
         if name == '.hgsub':
             data = '\n'.join([m.hgsub() for m in self.submoditer()])
             mode = ''

hgext/convert/gnuarch.py

@@ -137,9 +137,8 b' class gnuarch_source(converter_source, c'
         if rev != self.lastrev:
             raise util.Abort(_('internal calling inconsistency'))
 
-        # Raise IOError if necessary (i.e. deleted files).
         if not os.path.lexists(os.path.join(self.tmppath, name)):
-            raise IOError
+            return None, None
 
         return self._getfile(name, rev)
 

hgext/convert/hg.py

@@ -134,6 +134,8 b' class mercurial_sink(converter_sink):'
         def getfilectx(repo, memctx, f):
             v = files[f]
             data, mode = source.getfile(f, v)
+            if data is None:
+                return None
             if f == '.hgtags':
                 data = self._rewritetags(source, revmap, data)
             return context.memfilectx(self.repo, f, data, 'l' in mode,
@@ -351,8 +353,8 b' class mercurial_source(converter_source)'
         try:
             fctx = self.changectx(rev)[name]
             return fctx.data(), fctx.flags()
-        except error.LookupError, err:
-            raise IOError(err)
+        except error.LookupError:
+            return None, None
 
     def getchanges(self, rev):
         ctx = self.changectx(rev)

hgext/convert/monotone.py

@@ -282,11 +282,11 b' class monotone_source(converter_source, '
 
     def getfile(self, name, rev):
         if not self.mtnisfile(name, rev):
-            raise IOError # file was deleted or renamed
+            return None, None
         try:
             data = self.mtnrun("get_file_of", name, r=rev)
         except Exception:
-            raise IOError # file was deleted or renamed
+            return None, None
         self.mtnloadmanifest(rev)
         node, attr = self.files.get(name, (None, ""))
         return data, attr

hgext/convert/p4.py

@@ -183,7 +183,7 b' class p4_source(converter_source):'
                 contents += data
 
         if mode is None:
-            raise IOError(0, "bad stat")
+            return None, None
 
         if keywords:
             contents = keywords.sub("$\\1$", contents)

hgext/convert/subversion.py

@@ -933,7 +933,7 b' class svn_source(converter_source):'
     def getfile(self, file, rev):
         # TODO: ra.get_file transmits the whole file instead of diffs.
         if file in self.removed:
-            raise IOError
+            return None, None
         mode = ''
         try:
             new_module, revnum = revsplit(rev)[1:]
@@ -954,7 +954,7 b' class svn_source(converter_source):'
             notfound = (svn.core.SVN_ERR_FS_NOT_FOUND,
                 svn.core.SVN_ERR_RA_DAV_PATH_NOT_FOUND)
             if e.apr_err in notfound: # File not found
-                raise IOError
+                return None, None
             raise
         if mode == 'l':
             link_prefix = "link "
@@ -1236,9 +1236,8 b' class svn_sink(converter_sink, commandli'
 
         # Apply changes to working copy
         for f, v in files:
-            try:
-                data, mode = source.getfile(f, v)
-            except IOError:
+            data, mode = source.getfile(f, v)
+            if data is None:
                 self.delete.append(f)
             else:
                 self.putfile(f, mode, data)

hgext/histedit.py

@@ -283,7 +283,7 b' def collapse(repo, first, last, commitop'
                                       isexec='x' in flags,
                                       copied=copied.get(path))
             return mctx
-        raise IOError()
+        return None
 
     if commitopts.get('message'):
         message = commitopts['message']

hgext/largefiles/lfcommands.py

@@ -146,7 +146,7 b' def _addchangeset(ui, rsrc, rdst, ctx, r'
             try:
                 fctx = ctx.filectx(lfutil.standin(f))
             except error.LookupError:
-                raise IOError
+                return None
             renamed = fctx.renamed()
             if renamed:
                 renamed = lfutil.splitstandin(renamed[0])
@@ -248,7 +248,7 b' def _lfconvert_addchangeset(rsrc, rdst, '
             try:
                 fctx = ctx.filectx(srcfname)
             except error.LookupError:
-                raise IOError
+                return None
             renamed = fctx.renamed()
             if renamed:
                 # standin is always a largefile because largefile-ness
@@ -298,7 +298,7 b' def _getnormalcontext(repo, ctx, f, revm'
     try:
         fctx = ctx.filectx(f)
     except error.LookupError:
-        raise IOError
+        return None
     renamed = fctx.renamed()
     if renamed:
         renamed = renamed[0]

mercurial/cmdutil.py

@@ -2130,7 +2130,7 b' def amend(ui, repo, commitfunc, old, ext'
                                                   copied=copied.get(path))
                         return mctx
                     except KeyError:
-                        raise IOError
+                        return None
             else:
                 ui.note(_('copying changeset %s to %s\n') % (old, base))
 
@@ -2139,7 +2139,7 b' def amend(ui, repo, commitfunc, old, ext'
                     try:
                         return old.filectx(path)
                     except KeyError:
-                        raise IOError
+                        return None
 
                 user = opts.get('user') or old.user()
                 date = opts.get('date') or old.date()

mercurial/context.py

@@ -347,7 +347,10 b' class basectx(object):'
 def makememctx(repo, parents, text, user, date, branch, files, store,
                editor=None):
     def getfilectx(repo, memctx, path):
-        data, (islink, isexec), copied = store.getfile(path)
+        data, mode, copied = store.getfile(path)
+        if data is None:
+            return None
+        islink, isexec = mode
         return memfilectx(repo, path, data, islink=islink, isexec=isexec,
                                   copied=copied, memctx=memctx)
     extra = {}
@@ -1626,7 +1629,9 b' class memctx(committablectx):'
             self._repo.savecommitmessage(self._text)
 
     def filectx(self, path, filelog=None):
-        """get a file context from the working directory"""
+        """get a file context from the working directory
+
+        Returns None if file doesn't exist and should be removed."""
         return self._filectxfn(self._repo, self, path)
 
     def commit(self):

mercurial/localrepo.py

@@ -1394,9 +1394,12 b' class localrepository(object):'
                     self.ui.note(f + "\n")
                     try:
                         fctx = ctx[f]
-                        new[f] = self._filecommit(fctx, m1, m2, linkrev, trp,
-                                                  changed)
-                        m1.set(f, fctx.flags())
+                        if fctx is None:
+                            removed.append(f)
+                        else:
+                            new[f] = self._filecommit(fctx, m1, m2, linkrev,
+                                                      trp, changed)
+                            m1.set(f, fctx.flags())
                     except OSError, inst:
                         self.ui.warn(_("trouble committing %s!\n") % f)
                         raise
@@ -1404,9 +1407,7 b' class localrepository(object):'
                         errcode = getattr(inst, 'errno', errno.ENOENT)
                         if error or errcode and errcode != errno.ENOENT:
                             self.ui.warn(_("trouble committing %s!\n") % f)
-                            raise
-                        else:
-                            removed.append(f)
+                        raise
 
                 # update manifest
                 m1.update(new)

mercurial/patch.py

@@ -382,7 +382,7 b' class abstractbackend(object):'
 
     def getfile(self, fname):
         """Return target file data and flags as a (data, (islink,
-        isexec)) tuple.
+        isexec)) tuple. Data is None if file is missing/deleted.
         """
         raise NotImplementedError
 
@@ -426,7 +426,12 b' class fsbackend(abstractbackend):'
         except OSError, e:
             if e.errno != errno.ENOENT:
                 raise
-        return (self.opener.read(fname), (False, isexec))
+        try:
+            return (self.opener.read(fname), (False, isexec))
+        except IOError, e:
+            if e.errno != errno.ENOENT:
+                raise
+            return None, None
 
     def setfile(self, fname, data, mode, copysource):
         islink, isexec = mode
@@ -528,7 +533,7 b' class filestore(object):'
         if fname in self.data:
             return self.data[fname]
         if not self.opener or fname not in self.files:
-            raise IOError
+            return None, None, None
         fn, mode, copied = self.files[fname]
         return self.opener.read(fn), mode, copied
 
@@ -554,7 +559,7 b' class repobackend(abstractbackend):'
         try:
             fctx = self.ctx[fname]
         except error.LookupError:
-            raise IOError
+            return None, None
         flags = fctx.flags()
         return fctx.data(), ('l' in flags, 'x' in flags)
 
@@ -597,13 +602,12 b' class patchfile(object):'
         self.copysource = gp.oldpath
         self.create = gp.op in ('ADD', 'COPY', 'RENAME')
         self.remove = gp.op == 'DELETE'
-        try:
-            if self.copysource is None:
-                data, mode = backend.getfile(self.fname)
-                self.exists = True
-            else:
-                data, mode = store.getfile(self.copysource)[:2]
-                self.exists = backend.exists(self.fname)
+        if self.copysource is None:
+            data, mode = backend.getfile(self.fname)
+        else:
+            data, mode = store.getfile(self.copysource)[:2]
+        if data is not None:
+            self.exists = self.copysource is None or backend.exists(self.fname)
             self.missing = False
             if data:
                 self.lines = mdiff.splitnewlines(data)
@@ -622,7 +626,7 b' class patchfile(object):'
                             l = l[:-2] + '\n'
                         nlines.append(l)
                     self.lines = nlines
-        except IOError:
+        else:
             if self.create:
                 self.missing = False
             if self.mode is None:
@@ -1380,6 +1384,8 b' def _applydiff(ui, fp, patcher, backend,'
                 data, mode = None, None
                 if gp.op in ('RENAME', 'COPY'):
                     data, mode = store.getfile(gp.oldpath)[:2]
+                    # FIXME: failing getfile has never been handled here
+                    assert data is not None
                 if gp.mode:
                     mode = gp.mode
                     if gp.op == 'ADD':
@@ -1404,15 +1410,13 b' def _applydiff(ui, fp, patcher, backend,'
         elif state == 'git':
             for gp in values:
                 path = pstrip(gp.oldpath)
-                try:
-                    data, mode = backend.getfile(path)
-                except IOError, e:
-                    if e.errno != errno.ENOENT:
-                        raise
+                data, mode = backend.getfile(path)
+                if data is None:
                     # The error ignored here will trigger a getfile()
                     # error in a place more appropriate for error
                     # handling, and will not interrupt the patching
                     # process.
+                    pass
                 else:
                     store.setfile(path, data, mode)
         else: