Fix two bugs found by Clang's undefined behavior sanitizer.

- Return early from drawsprite_classic() if tspr->owner if oob.
  Commonize that check between renderers into bad_tspr().
- Make the BIT() macro a left-shift of the *unsigned* number 1,
  preventing expansion to (1<<31).

git-svn-id: https://svn.eduke32.com/eduke32@3717 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/build/src/engine.c

@@ -5586,7 +5586,16 @@ static void drawsprite_classic(int32_t snum)
     int32_t tilenum;
     int32_t cstat = tspr->cstat;
 
-    if ((unsigned)tspr->picnum >= MAXTILES || sec==NULL)
+    if (sec == NULL)
+        return;
+
+    if (bad_tspr(tspr))
+        return;
+
+    // This happens when using steroids.
+    // XXX: Should we instead run the code but handle stuff indexed by
+    // tspr->owner specially?
+    if ((unsigned)tspr->owner >= MAXSPRITES)
         return;
 
     DO_TILE_ANIM(tspr->picnum, spritenum+32768);

polymer/eduke32/build/src/engine_priv.h

@@ -93,6 +93,11 @@ void set_globalang(int16_t ang);
         if (picanm[Picnum].sf&PICANM_ANIMTYPE_MASK) Picnum += animateoffs(Picnum, Fakevar); \
     } while (0)
 
+static inline int32_t bad_tspr(const spritetype *tspr)
+{
+    return ((unsigned)tspr->owner >= MAXSPRITES || (unsigned)tspr->picnum >= MAXTILES);
+}
+
 void dorotspr_handle_bit2(int32_t *sx, int32_t *sy, int32_t *z, int32_t dastat,
                           int32_t cx1_plus_cx2, int32_t cy1_plus_cy2,
                           int32_t *ret_ouryxaspect, int32_t *ret_ourxyaspect);

polymer/eduke32/build/src/polymer.c

@@ -1342,7 +1342,8 @@ void                polymer_drawsprite(int32_t snum)
 
     tspr = tspriteptr[snum];
 
-    if (tspr->owner < 0 || tspr->picnum < 0) return;
+    if (bad_tspr(tspr))
+        return;
 
     if ((tspr->cstat & 8192) && (depth && !mirrors[depth-1].plane))
         return;

polymer/eduke32/build/src/polymost.c

@@ -4875,7 +4875,8 @@ void polymost_drawsprite(int32_t snum)
     int32_t tsizx, tsizy;
 
     tspr = tspriteptr[snum];
-    if (tspr->owner < 0 || tspr->picnum < 0 || tspr->picnum >= MAXTILES) return;
+    if (bad_tspr(tspr))
+        return;
 
     spritenum         = tspr->owner;
 

polymer/eduke32/source/macros.h

@@ -43,7 +43,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
 // mask definitions
 
-#define BIT(shift)     (1<<(shift))
+#define BIT(shift)     (1u<<(shift))
 
 #define TEST_SYNC_KEY(bits, sync_num) TEST(bits, BIT(sync_num))
 

polymer/eduke32/source/sector.c

@@ -2492,7 +2492,7 @@ void P_HandleSharedKeys(int32_t snum)
             }
         }
 
-    j = sb_snum & ((15<<SK_WEAPON_BITS)|BIT(SK_STEROIDS)|BIT(SK_NIGHTVISION)|BIT(SK_MEDKIT)|BIT(SK_QUICK_KICK)| \
+    j = sb_snum & ((15u<<SK_WEAPON_BITS)|BIT(SK_STEROIDS)|BIT(SK_NIGHTVISION)|BIT(SK_MEDKIT)|BIT(SK_QUICK_KICK)| \
                    BIT(SK_HOLSTER)|BIT(SK_INV_LEFT)|BIT(SK_PAUSE)|BIT(SK_HOLODUKE)|BIT(SK_JETPACK)|BIT(SK_INV_RIGHT)| \
                    BIT(SK_TURNAROUND)|BIT(SK_OPEN)|BIT(SK_INVENTORY)|BIT(SK_ESCAPE));
     sb_snum = j & ~p->interface_toggle_flag;