test-convert-git: Use ~ instead of ^
Solaris sh interprets ^ as pipe symbol and the test thus failed in strange
ways. git can however use of HEAD~ instead of HEAD^.
adding a
now at: a.patch
applying b.patch
applying c.patch
now at: c.patch
now at: b.patch
% Using index
now at: a.patch
applying b.patch
applying c.patch
now at: c.patch
% No warnings when using index
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