sneak/rgoue
1
0
Fork 0
Code Issues 10 Pull Requests Actions Packages Projects Releases Wiki Activity

fix: bound wizard-created Which against its item table (closes #10)

Browse Source 
createObj stored the raw 0-f nibble as Object.Which with no bounds
check, so wizard mode -> C -> / -> f made a wand numbered 15 against a
14-entry table and panicked in fixStick; input below 'a' or '0' went
negative and panicked the same way. C's create_obj() was equally
unchecked, but its consumers were either switches (defined for any
value) or static-array reads past the end (undefined, and survivable in
practice). Since one game is now one process, the Go panic kills the
game outright and leaves the terminal in raw mode.

Reject at the two boundaries a bad Which can enter through. createObj
now refuses an out-of-range choice with a message drawn from C's own
type_name() vocabulary and adds nothing to the pack, a deliberate
divergence recorded in a comment because C had no defined behavior here
to be faithful to. Restore refuses a snapshot describing such an object
(ErrSaveCorrupt) rather than loading a game that would explode later.

Behind those, whichLimit/hasValidWhich back defensive guards at every
dispatch the issue names: the quaffHandler/readHandler/zapHandler
accessors return no handler instead of indexing (for wands that is
exactly what non-MASTER C did, matching no case and still running
o_charges--), the callIt lore lookups, identifyType, armorClass for the
a_class[] reads, initWeapon against the missing init_dam[] row for
WeaponFlame, fixStick's ws_type[] read, and inventoryName and
objectWorth, hoisted so one check each covers the whole family of
per-kind name and appraisal tables.

No in-range input changes behavior and no guard consumes a random
number: the rejection precedes every rnd() call. TestSeedCompatItemTables
stays green untouched.

New game/wizard_test.go covers the exact reproducer, a rejection sweep
over every indexed kind including both negative-input forms, an
acceptance sweep proving valid choices still build the right item, one
no-panic test per guarded family, the fixStick crash site, the
corrupt-save rejection, and a check that whichLimit still agrees with
the table sizes. Each guard was confirmed load-bearing by reverting it
and watching the test panic.

TODO.md records the step; Next Step is deliberately left alone, since
this arrived out of band via an issue.
This commit is contained in:
Jeffrey Paul
2026-08-09 05:09:03 +00:00
parent eb31473ef0
commit 9dbd9d11cb
12 changed files with 660 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
game/wizard.go
View File

@@ -26,6 +26,21 @@ func (g *RogueGame) createObj() {
obj.Count = 1
g.Msgs.Mpos = 0
// Deliberate divergence from 5.4.4: C stored this nibble unchecked, so
// 'a'-'f' (and anything below '0' or 'a', which goes negative) indexed
// straight past the ends of the per-kind static tables. That was
// undefined behavior C happened to survive by reading adjacent memory;
// in Go it is a panic that kills the process with the terminal still in
// raw mode. C had no defined behavior here to be faithful to, so the
// choice is rejected outright rather than emulating a garbage read. The
// check precedes every rnd() call below, so the RNG sequence is
// untouched either way.
if !obj.wizardCanCreate() {
g.msg("there is no such %s", obj.Kind)
return
}
//nolint:exhaustive // C-faithful: only the cases C handled (approved 2026-07-07)
switch obj.Kind {
case KindWeapon, KindArmor:
@@ -71,7 +86,7 @@ func (g *RogueGame) createWeaponArmor(obj *Object) {
return
}
obj.ArmorClass = g.data.aClass[obj.Which]
obj.ArmorClass = g.data.armorClass(obj.Which)
if bless == '-' {
obj.ArmorClass += g.rnd(3) + 1
}