builtin-am: reject patches when there's a session in progress

Since d1c5f2a (Add git-am, applymbox replacement., 2005-10-07), git-am
would error out if the user gave it mbox(s) on the command-line, but
there was a session in progress.

Since c95b138 (Fix git-am safety checks, 2006-09-15), git-am would
detect if the user attempted to feed it a mbox via stdin, by checking if
stdin is not a tty and there is no resume command given.

Re-implement the above two safety checks.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/am.c b/builtin/am.c
index 6c24d075c28a759a2a8ec9032e970064af5dff3b..d4b4b86be99fcca7235d62e14eae2866be67fd47 100644 (file)
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1148,6 +1148,21 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                die(_("failed to read the index"));
 
        if (am_in_progress(&state)) {
+               /*
+                * Catch user error to feed us patches when there is a session
+                * in progress:
+                *
+                * 1. mbox path(s) are provided on the command-line.
+                * 2. stdin is not a tty: the user is trying to feed us a patch
+                *    from standard input. This is somewhat unreliable -- stdin
+                *    could be /dev/null for example and the caller did not
+                *    intend to feed us a patch but wanted to continue
+                *    unattended.
+                */
+               if (argc || (resume == RESUME_FALSE && !isatty(0)))
+                       die(_("previous rebase directory %s still exists but mbox given."),
+                               state.dir);
+
                if (resume == RESUME_FALSE)
                        resume = RESUME_APPLY;