add: support adding explicit files in subrepos

Change the behavior of the add command such that explicit paths in
subrepos are always added.  This eliminates the previous behavior
where if you called "hg add" for an explicit path in a subrepo
without specifying the -S option, it would be silently ignored.
If you specify patterns, or no arguments at all, the -S option
will still be needed to activate recursion into subrepos.

mercurial/cmdutil.py

@@ -1165,15 +1165,19 b' def add(ui, repo, match, dryrun, listsub'
             if ui.verbose or not exact:
                 ui.status(_('adding %s\n') % match.rel(join(f)))
 
-    if listsubrepos:
-        for subpath in wctx.substate:
-            sub = wctx.sub(subpath)
-            try:
-                submatch = matchmod.narrowmatcher(subpath, match)
+    for subpath in wctx.substate:
+        sub = wctx.sub(subpath)
+        try:
+            submatch = matchmod.narrowmatcher(subpath, match)
+            if listsubrepos:
                 bad.extend(sub.add(ui, submatch, dryrun, prefix))
-            except error.LookupError:
-                ui.status(_("skipping missing subrepository: %s\n")
-                               % join(subpath))
+            else:
+                for f in sub.walk(submatch):
+                    if submatch.exact(f):
+                        bad.extend(sub.add(ui, submatch, dryrun, prefix))
+        except error.LookupError:
+            ui.status(_("skipping missing subrepository: %s\n")
+                           % join(subpath))
 
     if not dryrun:
         rejected = wctx.add(names, prefix)

mercurial/help/subrepos.txt

@@ -73,7 +73,9 b' Interaction with Mercurial Commands'
 -----------------------------------
 
 :add: add does not recurse in subrepos unless -S/--subrepos is
-    specified. Subversion subrepositories are currently silently
+    specified.  However, if you specify the full path of a file in a
+    subrepo, it will be added even without -S/--subrepos specified.
+    Subversion subrepositories are currently silently
     ignored.
 
 :archive: archive does not recurse in subrepositories unless

mercurial/subrepo.py

@@ -353,6 +353,12 b' class abstractsubrepo(object):'
                         unit=_('files'), total=total)
         ui.progress(_('archiving (%s)') % relpath, None)
 
+    def walk(self, match):
+        '''
+        walk recursively through the directory tree, finding all files
+        matched by the match function
+        '''
+        pass
 
 class hgsubrepo(abstractsubrepo):
     def __init__(self, ctx, path, state):
@@ -543,6 +549,9 b' class hgsubrepo(abstractsubrepo):'
         ctx = self._repo[rev]
         return ctx.flags(name)
 
+    def walk(self, match):
+        ctx = self._repo[None]
+        return ctx.walk(match)
 
 class svnsubrepo(abstractsubrepo):
     def __init__(self, ctx, path, state):

tests/test-subrepo.t

@@ -892,7 +892,7 b' Test behavior of add for explicit path i'
   $ hg init s
   $ hg ci -m0
   committing subrepository s
-Adding with an explicit path in a subrepo currently fails silently
+Adding with an explicit path in a subrepo adds the file
   $ echo c1 > f1
   $ echo c2 > s/f2
   $ hg st -S
@@ -900,14 +900,13 b' Adding with an explicit path in a subrep'
   ? s/f2
   $ hg add s/f2
   $ hg st -S
+  A s/f2
   ? f1
-  ? s/f2
-  $ hg ci -R s -Am0
-  adding f2
+  $ hg ci -R s -m0
   $ hg ci -Am1
   adding f1
   committing subrepository s
-Adding with an explicit path in a subrepo with -S adds the file
+Adding with an explicit path in a subrepo with -S has the same behavior
   $ echo c3 > f3
   $ echo c4 > s/f4
   $ hg st -S