stash: allow "git stash -p <pathspec>" to assume push again
Historically "git stash [<options>]" was assumed to mean "git stash save [<options>]". Since 1ada5020b38 (stash: use stash_push for no verb form, 2017-02-28) it is assumed to mean "git stash push [<options>]". As the push subcommand supports pathspecs, 9e140909f61 (stash: allow pathspecs in the no verb form, 2017-02-28) allowed "git stash -p <pathspec>" to mean "git stash push -p <pathspec>". This was broken in 8c3713cede7 (stash: eliminate crude option parsing, 2020-02-17) which failed to account for "push" being added to the start of argv in cmd_stash() before it calls push_stash() and kept looking in argv[0] for "-p" after moving the code to push_stash(). Fix this by regression by checking argv[1] instead of argv[0] and add a couple of tests to prevent future regressions. Helped-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>