[PATCH v4 0/9] stash: modifiy handling of stash-like references

This series teaches git stash branch and git stash show to be more tolerant of stash-like references that are not actually stash entry references, while teaching git stash pop and git stash drop to be less tolerant of stash-like references that are not actually stash entry references.

Junio: I did not adopt your suggestion to make git stash drop more tolerant
of invalid stash references since failing early might help a user
to spot an incorrect assumption about the state of their working tree
and stash stack - silently handling this case might hide such an incorrect
assumption. However, if you would prefer git stash drop to behave that
way, I'll rework the series accordingly.

The first 3 commits refactor the existing code without significantly changing existing behaviour.

The next 4 commits modify existing behaviour to be more (or less) tolerant of stash-like references, as required.

The last 2 commits update the tests and documentation to reflect the modified behaviour.

Thanks to Johannes Sixt for suggesting improvements to the tests.

This series in unchanged from v3 except for patch 8 which improves the tests and patch 9 which enhances the documentation to indicate which commands require a stash entry reference and which are happy to use just a stash-like commit.

Jon Seymour (9):
  stash: refactor - create pop_stash function
  stash: extract stash-like check into its own function
  stash: introduce is_stash_ref and assert_stash_ref functions.
  stash: teach git stash pop to fail early if the argument is not a
    stash ref
  stash: teach git stash drop to fail early if the specified revision
    is not a stash reference
  stash: teach git stash branch to tolerate stash-like arguments
  stash: teach git stash show to always tolerate stash-like arguments.
  t3903-stash.sh: tests of git stash with stash-like arguments
  Documentation: git stash branch now tolerates non-stash references.

 Documentation/git-stash.txt |   37 +++++++++--------
 git-stash.sh                |   92 +++++++++++++++++++++++++++++++------------
 t/t3903-stash.sh            |   77 ++++++++++++++++++++++++++++++++++++
 3 files changed, 163 insertions(+), 43 deletions(-)