Backport ignoring values outside lightgrid to OpenGL1

Fixes possibly of reading memory past end of lightGridData or reading
wrong light grid data (wrapping around to next row).

code/renderergl1/tr_light.c

@@ -182,6 +182,9 @@ static void R_SetupEntityLightingGrid( trRefEntity_t *ent ) {
 		data = gridData;
 		for ( j = 0 ; j < 3 ; j++ ) {
 			if ( i & (1<<j) ) {
+				if ( pos[j] + 1 > tr.world->lightGridBounds[j] - 1 ) {
+					break; // ignore values outside lightgrid
+				}
 				factor *= frac[j];
 				data += gridStep[j];
 			} else {
@@ -189,6 +192,9 @@ static void R_SetupEntityLightingGrid( trRefEntity_t *ent ) {
 			}
 		}
 
+		if ( j != 3 ) {
+			continue;
+		}
 		if ( !(data[0]+data[1]+data[2]) ) {
 			continue;	// ignore samples in walls
 		}

code/renderergl2/tr_light.c

@@ -180,18 +180,15 @@ static void R_SetupEntityLightingGrid( trRefEntity_t *ent, world_t *world ) {
 		byte	*data;
 		int		lat, lng;
 		vec3_t	normal;
-		qboolean ignore;
 		#if idppc
 		float d0, d1, d2, d3, d4, d5;
 		#endif
 		factor = 1.0;
 		data = gridData;
-		ignore = qfalse;
 		for ( j = 0 ; j < 3 ; j++ ) {
 			if ( i & (1<<j) ) {
-				if ((pos[j] + 1) > world->lightGridBounds[j] - 1)
-				{
-					ignore = qtrue; // ignore values outside lightgrid
+				if ( pos[j] + 1 > world->lightGridBounds[j] - 1 ) {
+					break; // ignore values outside lightgrid
 				}
 				factor *= frac[j];
 				data += gridStep[j];
@@ -200,8 +197,9 @@ static void R_SetupEntityLightingGrid( trRefEntity_t *ent, world_t *world ) {
 			}
 		}
 
-		if ( ignore )
+		if ( j != 3 ) {
 			continue;
+		}
 
 		if (world->hdrLightGrid)
 		{