adding a
popping c.patch
popping b.patch
now at: a.patch
applying b.patch
applying c.patch
now at: c.patch
popping c.patch
now at: b.patch

% Using index
popping b.patch
now at: a.patch
applying b.patch
applying c.patch
now at: c.patch

% No warnings when using index
popping bug141421
popping bug314159
popping c.patch
now at: b.patch
applying c.patch
applying bug314159
now at: bug314159

% Detect ambiguous non-index
patch name "14" is ambiguous:
  bug314159
  bug141421
abort: patch 14 not in series