subrepo: don't crash when git .hgsubstate is empty (issue2716)

mercurial/subrepo.py

@@ -808,7 +808,7 b' class gitsubrepo(abstractsubrepo):'
 
     def dirty(self, ignoreupdate=False):
         if self._gitmissing():
-            return True
+            return self._state[1] != ''
         if not ignoreupdate and self._state[1] != self._gitstate():
             # different version checked out
             return True
@@ -818,6 +818,9 b' class gitsubrepo(abstractsubrepo):'
 
     def get(self, state, overwrite=False):
         source, revision, kind = state
+        if not revision:
+            self.remove()
+            return
         self._fetch(source, revision)
         # if the repo was set to be bare, unbare it
         if self._gitcommand(['config', '--bool', 'core.bare']) == 'true':
@@ -935,6 +938,8 b' class gitsubrepo(abstractsubrepo):'
             mergefunc()
 
     def push(self, force):
+        if not self._state[1]:
+            return True
         if self._gitmissing():
             raise util.Abort(_("subrepo %s is missing") % self._relpath)
         # if a branch in origin contains the revision, nothing to do
@@ -991,6 +996,8 b' class gitsubrepo(abstractsubrepo):'
 
     def archive(self, ui, archiver, prefix):
         source, revision = self._state
+        if not revision:
+            return
         self._fetch(source, revision)
 
         # Parse git's native archive command.
@@ -1015,10 +1022,10 b' class gitsubrepo(abstractsubrepo):'
 
 
     def status(self, rev2, **opts):
-        if self._gitmissing():
+        rev1 = self._state[1]
+        if self._gitmissing() or not rev1:
             # if the repo is missing, return no results
             return [], [], [], [], [], [], []
-        rev1 = self._state[1]
         modified, added, removed = [], [], []
         if rev2:
             command = ['diff-tree', rev1, rev2]

tests/test-subrepo-git.t

@@ -334,6 +334,33 b" Don't crash if the subrepo is missing"
   $ hg sum | grep commit
   commit: (clean)
 
+Don't crash if the .hgsubstate entry is missing
+
+  $ hg update 1 -q
+  $ hg rm .hgsubstate
+  $ hg commit .hgsubstate -m 'no substate'
+  created new head
+  $ hg tag -l nosubstate
+  $ hg manifest
+  .hgsub
+  a
+
+  $ hg status -S
+  $ hg sum | grep commit
+  commit: 1 subrepos
+
+  $ hg commit -m 'restore substate'
+  committing subrepository s
+  $ hg manifest
+  .hgsub
+  .hgsubstate
+  a
+  $ hg sum | grep commit
+  commit: (clean)
+
+  $ hg update -qC nosubstate
+  $ ls s
+
 Check hg update --clean
   $ cd $TESTTMP/ta
   $ echo  > s/g