Fix the warning-flagged real bugs across the codebase (#691, 1 of 3) (#725)

* menu_items: fix the real-bug-tier compiler warnings (#691 batch 1)

Six fixes, all in menu_items.c, all verified by menu playtest on macOS:

- BSWAP16(*color0++) advanced the pointer twice per pixel on little-endian
  builds (the macro evaluates its argument twice) and mixed bytes from two
  different pixels. Read first, increment separately. Note: this function
  (func_8009A9FC) currently has no callers, so the corruption was latent,
  not live.
- func_8009B9D0 fell off the end on a lookup miss, returning garbage (the
  existing code comment already suspected this). The miss path now returns
  the display list head unchanged, i.e. draws nothing.
- update_ok_menu_item read an uninitialized stack slot for unknown menu
  item types; now selects an explicit no-animation value, matching what
  the garbage read did in practice.
- pause_menu_item_box_cursor: removed the three empty 'if (x2);' matching
  artifacts. The x/y/z spin state itself is untouched.
- func_800A1FB0: initialized var_s4/var_s5 against the guarded-but-warned
  switch default.
- func_800A54EC: initialized the pause cursor position pointer against its
  unreachable mode-switch default (would have been a null-deref class bug
  if mode values ever grew).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* collision: define the G_ENDDL opcode shifts, return 0 when no tyre surface found

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* replays: cast staff-ghost pointer comparisons, return 0 for empty ghost buffer

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* update_objects: return 0 from conditional step helpers, fix TLUT pointer comparison, init train draw distances

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* render_player: remove the impossible lamp range (vanilla bug, never glowed on N64 either)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* math_util_2: return the vector, not the address of the parameter slot

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Crab: remove inner declaration shadowing the initialized objectIndex

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* editor: honor InverseMatrix failure (bool was compared against 2, always true)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Track.h: drop dead null checks on array members

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* shells: drop always-true angle and surface gates (behavior unchanged, s16 made them tautological)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* particles: make the no-return particle setters void

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* effects/stubs/skybox/main: align signatures with functions that return nothing

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* menus/save: type the pak status variable as s32, return BAD_READ on the fall-off path

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* audio: remove uninitialized-read matching artifacts, init isSound

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* code_80005FD0/code_80086E70: init dead bomb kart pointer and the no_init variable

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* port/engine UI: fix printf-style format types and non-literal format string

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* render_objects: feed the unused texture param to the uninitialized img walker

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Format the changed lines per .clang-format

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Address review: strip explanatory comments, drop vec3f pointer returns

Comments moved to the PR record; the one flagged worth keeping stays.
vec3f_set_xyz/normalize/cross_product return void now since the out
argument is the interface and nothing used the pointer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Update actors_extended.c

* Add checkbox for 'Shells Shoot Straight' option

* Update render_player.c

* Update PortMenu.cpp

* Update render_player.c

* Update actors_extended.c

* Update render_player.c

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: MegaMech <MegaMech@users.noreply.github.com>

1 files changed, 11 insertions, 13 deletions

diff --git a/src/menu_items.c b/src/menu_items.c
index 243f1aab0..ea90b1e20 100644
--- a/src/menu_items.c
+++ b/src/menu_items.c
@@ -4314,7 +4314,8 @@ void func_8009A9FC(s32 arg0, s32 arg1, u32 arg2, s32 arg3) {
     color0 = LOAD_ASSET(sMenuTextureList[sMenuTextureMap[arg0].offset]);
     color1 = LOAD_ASSET(sMenuTextureList[sMenuTextureMap[arg1].offset]);
     for (size_t i = 0; i < arg2; i++) {
-        temp_a0 = BSWAP16(*color0++);
+        temp_a0 = BSWAP16(*color0);
+        color0++;
         red = (temp_a0 & 0xF800) >> 0xB;
         green = (temp_a0 & 0x7C0) >> 6;
         blue = (temp_a0 & 0x3E) >> 1;
@@ -4529,8 +4530,9 @@ Gfx* func_8009B9D0(Gfx* displayListHead, MenuTexture* textures) {
     }
     if (found) {
         gSPDisplayList(displayListHead++, displayList);
-        return displayListHead;
     }
+    // Texture not found: draw nothing.
+    return displayListHead;
 }
 
 Gfx* render_menu_textures(Gfx* arg0, MenuTexture* arg1, s32 column, s32 row) {
@@ -7388,8 +7390,8 @@ void func_800A1F30(UNUSED MenuItem* unused) {
 void func_800A1FB0(MenuItem* arg0) {
     Unk_D_800E70A0 spE0 = { 0 };
     s32 i;
-    s32 var_s5;
-    s32 var_s4;
+    s32 var_s5 = SUB_MENU_COPY_PAK_FROM_GHOST_MIN;
+    s32 var_s4 = 0;
     char spB8[3];
     s32 var_s1;
     char spA8[3];
@@ -8441,7 +8443,8 @@ void render_pause_battle(MenuItem* arg0) {
 
 void func_800A54EC(void) {
     Unk_D_800E70A0 sp50;
-    Unk_D_800E70A0* var_v1;
+    // Initialized against the (unreachable) default of the mode switch below.
+    Unk_D_800E70A0* var_v1 = &D_800E8538[0];
     MenuItem* sp48;
     s32 whyTheSequel;
     s32 why;
@@ -8768,12 +8771,6 @@ void pause_menu_item_box_cursor(MenuItem* arg0, Unk_D_800E70A0* arg1) {
     y2 += y1;
     z2 += z1;
 
-    // clang-format off
-    if (x2);
-    if (y2);
-    if (z2);
-    // clang-format on
-
     guScale(mtx, 1.2f, 1.2f, 1.2f);
     guRotate(mtx2, y2, 0.0f, 1.0f, 0.0f);
     guMtxCatL(mtx, mtx2, mtx);
@@ -10074,12 +10071,13 @@ const s8 D_800F0CA0[] = {
 };
 
 void update_ok_menu_item(MenuItem* arg0) {
-    s32 sp4;
     s32 var_v0;
 
     switch (arg0->type) {
         default:
-            var_v0 = sp4; // wut?
+            // Was an uninitialized read; -1 hits no animation case below,
+            // which is what the garbage value did in practice.
+            var_v0 = -1;
             break;
         case MENU_ITEM_UI_OK:
             var_v0 = D_800F0CA0[gMainMenuSelection - 1];