tests: add test showing crash when shelving ghosted rename target

When you `hg rename` a file and then delete the rename target, `hg
shelve` will give you a traceback.

Note that the shelve succeeds and the shelve is correct, it's just the
update to the parent that fails (i.e. to the parent of the commit that
was created for the shelve).

This can be squashed into the next commit if the reviewer prefers.

Differential Revision: https://phab.mercurial-scm.org/D8045

tests/test-shelve.t

@@ -171,6 +171,8 set up some more complex changes to shel
   $ hg mv b b.rename
   moving b/b to b.rename/b
   $ hg cp c c.copy
+  $ hg mv d ghost
+  $ rm ghost
   $ hg status -C
   M a/a
   A b.rename/b
@@ -178,12 +180,20 set up some more complex changes to shel
   A c.copy
     c
   R b/b
+  R d
+  ! ghost
+    d
 
 the common case - no options or filenames
 
-  $ hg shelve
-  shelved as default-01
-  2 files updated, 0 files merged, 2 files removed, 0 files unresolved
+  $ hg shelve 2>&1 | grep KeyError
+  KeyError: 'No such manifest entry.' (no-pure !)
+      raise KeyError (pure !)
+  KeyError (pure !)
+# Get out of the broken state so later tests work
+  $ hg forget b.rename/b c.copy ghost
+  $ hg revert a/a b/b d
+  $ rm a/a.orig b.rename/b c.copy
   $ hg status -C
 
 ensure that our shelved changes exist
@@ -254,6 +264,7 removed, even though there are more than
   A c.copy
     c
   R b/b
+  R d
   $ hg shelve -l
 
 (both of default.hg and default-1.hg should be still kept, because it
@@ -287,6 +298,7 named shelves, specific filenames, and "
   A c.copy
     c
   R b/b
+  R d
   $ HGEDITOR=cat hg shelve -q -n wibble -m wat -e a
   wat
   
@@ -306,6 +318,7 expect "a" to no longer be present, but
   A c.copy
     c
   R b/b
+  R d
   $ hg shelve -l --stat
   wibble          (*)    wat (glob)
    a/a |  1 +
@@ -323,6 +336,7 and now "a/a" should reappear
   A c.copy
     c
   R b/b
+  R d
 
 ensure old shelve backups are being deleted automatically
 
@@ -363,6 +377,7 force a conflicted merge to occur
   M b.rename/b
   M c.copy
   R b/b
+  R d
   ? a/a.orig
   # The repository is in an unfinished *unshelve* state.
   
@@ -381,10 +396,10 ensure that we have a merge with unresol
 #if phasebased
   $ hg heads -q --template '{rev}\n'
   8
-  5
+  6
   $ hg parents -q --template '{rev}\n'
   8
-  5
+  6
 #endif
 
 #if stripbased
@@ -401,6 +416,7 ensure that we have a merge with unresol
   M b.rename/b
   M c.copy
   R b/b
+  R d
   ? a/a.orig
   $ hg diff
   diff --git a/a/a b/a/a
@@ -412,13 +428,19 ensure that we have a merge with unresol
    c
   +=======
   +a
-  +>>>>>>> working-copy: a68ec3400638 - shelve: changes to: [mq]: second.patch
+  +>>>>>>> working-copy: 203c9f771d2b - shelve: changes to: [mq]: second.patch
   diff --git a/b/b b/b.rename/b
   rename from b/b
   rename to b.rename/b
   diff --git a/c b/c.copy
   copy from c
   copy to c.copy
+  diff --git a/d b/d
+  deleted file mode 100644
+  --- a/d
+  +++ /dev/null
+  @@ -1,1 +0,0 @@
+  -d
   $ hg resolve -l
   U a/a
 
@@ -434,6 +456,7 abort the unshelve and be happy
   M b.rename/b
   M c.copy
   R b/b
+  R d
   ? a/a.orig
   $ hg unshelve -a
   unshelve of 'default' aborted
@@ -512,6 +535,7 ensure the repo is as we hope
     c
   A foo/foo
   R b/b
+  R d
   ? a/a.orig
 
 there should be no shelves left