rebase: flag --apply and --merge as incompatible

Previously, we flagged options which implied --apply as being
incompatible with options which implied --merge.  But if both options
were given explicitly, then we didn't flag the incompatibility.  The
same is true with --apply and --interactive.  Add the check, and add
some testcases to verify these are also caught.

Signed-off-by: Elijah Newren <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: newren

builtin/rebase.c

@@ -907,6 +907,9 @@ static int parse_opt_am(const struct option *opt, const char *arg, int unset)
 	BUG_ON_OPT_NEG(unset);
 	BUG_ON_OPT_ARG(arg);
 
+	if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_APPLY)
+	    die(_("apply options and merge options cannot be used together"));
+
 	opts->type = REBASE_APPLY;
 
 	return 0;
@@ -920,8 +923,10 @@ static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 	BUG_ON_OPT_NEG(unset);
 	BUG_ON_OPT_ARG(arg);
 
-	if (!is_merge(opts))
-		opts->type = REBASE_MERGE;
+	if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
+	    die(_("apply options and merge options cannot be used together"));
+
+	opts->type = REBASE_MERGE;
 
 	return 0;
 }
@@ -935,6 +940,9 @@ static int parse_opt_interactive(const struct option *opt, const char *arg,
 	BUG_ON_OPT_NEG(unset);
 	BUG_ON_OPT_ARG(arg);
 
+	if (opts->type != REBASE_UNSPECIFIED && opts->type != REBASE_MERGE)
+	    die(_("apply options and merge options cannot be used together"));
+
 	opts->type = REBASE_MERGE;
 	opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 

t/t3422-rebase-incompatible-options.sh

@@ -67,7 +67,10 @@ test_rebase_am_only () {
 
 }
 
+# Check options which imply --apply
 test_rebase_am_only --whitespace=fix
 test_rebase_am_only -C4
+# Also check an explicit --apply
+test_rebase_am_only --apply
 
 test_done