Reject a scrollback above TERM_SCROLLBACK_MAX

term_new() silently cut a scrollback above 1000000 lines to 1000000.
The limit now has a name in term.h, and term_new() returns NULL above
it, as it does for the other invalid options.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/api_args_test.c b/tests/api_args_test.c
index 18af728..6c7dfc7 100644
--- a/tests/api_args_test.c
+++ b/tests/api_args_test.c
@@ -75,6 +75,16 @@ static void test_new_rejects_bad_options(void)
     assert(!term_new(&opt));
 
     memset(&opt, 0, sizeof(opt));
+    opt.scrollback = TERM_SCROLLBACK_MAX + 1;
+    assert(!term_new(&opt));
+
+    memset(&opt, 0, sizeof(opt));
+    opt.scrollback = TERM_SCROLLBACK_MAX;
+    struct term *max = term_new(&opt);
+    assert(max);
+    term_free(max);
+
+    memset(&opt, 0, sizeof(opt));
     opt.cursor_style = (enum term_cursor_style)3;
     assert(!term_new(&opt));