econsplit.diff

diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index 8fea6953a..4d1516cf0 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -2461,39 +2461,30 @@ static void ReportNewsProductionChangeIndustry(Industry *ind, CargoID type, int
 static const uint PERCENT_TRANSPORTED_60 = 153;
 static const uint PERCENT_TRANSPORTED_80 = 204;
 
-/**
- * Change industry production or do closure
- * @param i Industry for which changes are performed
- * @param monthly true if it's the monthly call, false if it's the random call
- */
-static void ChangeIndustryProduction(Industry *i, bool monthly)
+static byte ChangeIndustryProductionOriginal(Industry *i, bool monthly, StringID *str, bool *suppress_message)
 {
-	StringID str = STR_NULL;
-	bool closeit = false;
-	const IndustrySpec *indspec = GetIndustrySpec(i->type);
 	bool standard = false;
-	bool suppress_message = false;
-	bool recalculate_multipliers = false; ///< reinitialize production_rate to match prod_level
-	/* don't use smooth economy for industries using production related callbacks */
-	bool smooth_economy = indspec->UsesSmoothEconomy();
 	byte div = 0;
 	byte mul = 0;
 	int8 increment = 0;
 
+	byte new_prod_level = i->prod_level;
+
+	const IndustrySpec *indspec = GetIndustrySpec(i->type);
 	bool callback_enabled = HasBit(indspec->callback_mask, monthly ? CBM_IND_MONTHLYPROD_CHANGE : CBM_IND_PRODUCTION_CHANGE);
 	if (callback_enabled) {
 		uint16 res = GetIndustryCallback(monthly ? CBID_INDUSTRY_MONTHLYPROD_CHANGE : CBID_INDUSTRY_PRODUCTION_CHANGE, 0, Random(), i, i->type, i->location.tile);
 		if (res != CALLBACK_FAILED) { // failed callback means "do nothing"
-			suppress_message = HasBit(res, 7);
+			*suppress_message = HasBit(res, 7);
 			/* Get the custom message if any */
-			if (HasBit(res, 8)) str = MapGRFStringID(indspec->grf_prop.grffile->grfid, GB(GetRegister(0x100), 0, 16));
+			if (HasBit(res, 8)) *str = MapGRFStringID(indspec->grf_prop.grffile->grfid, GB(GetRegister(0x100), 0, 16));
 			res = GB(res, 0, 4);
 			switch (res) {
 				default: NOT_REACHED();
 				case 0x0: break;                  // Do nothing, but show the custom message if any
 				case 0x1: div = 1; break;         // Halve industry production. If production reaches the quarter of the default, the industry is closed instead.
 				case 0x2: mul = 1; break;         // Double industry production if it hasn't reached eight times of the original yet.
-				case 0x3: closeit = true; break;  // The industry announces imminent closure, and is physically removed from the map next month.
+				case 0x3: new_prod_level = PRODLEVEL_MINIMUM; break;  // The industry announces imminent closure, and is physically removed from the map next month.
 				case 0x4: standard = true; break; // Do the standard random production change as if this industry was a primary one.
 				case 0x5: case 0x6: case 0x7:     // Divide production by 4, 8, 16
 				case 0x8: div = res - 0x3; break; // Divide production by 32
@@ -2504,120 +2495,129 @@ static void ChangeIndustryProduction(Industry *i, bool monthly)
 					increment = res == 0x0D ? -1 : 1;
 					break;
 				case 0xF:                         // Set production to third byte of register 0x100
-					i->prod_level = Clamp(GB(GetRegister(0x100), 16, 8), PRODLEVEL_MINIMUM, PRODLEVEL_MAXIMUM);
-					recalculate_multipliers = true;
+					new_prod_level = Clamp(GB(GetRegister(0x100), 16, 8), PRODLEVEL_MINIMUM, PRODLEVEL_MAXIMUM);
 					break;
 			}
 		}
 	} else {
-		if (monthly != smooth_economy) return;
-		if (indspec->life_type == INDUSTRYLIFE_BLACK_HOLE) return;
+		if (indspec->life_type == INDUSTRYLIFE_BLACK_HOLE) return new_prod_level;
 	}
 
 	if (standard || (!callback_enabled && (indspec->life_type & (INDUSTRYLIFE_ORGANIC | INDUSTRYLIFE_EXTRACTIVE)) != 0)) {
 		/* decrease or increase */
 		bool only_decrease = (indspec->behaviour & INDUSTRYBEH_DONT_INCR_PROD) && _settings_game.game_creation.landscape == LT_TEMPERATE;
+		if (only_decrease || Chance16(1, 3)) {
+			/* If more than 60% transported, 66% chance of increase, else 33% chance of increase */
+			if (!only_decrease && (i->last_month_pct_transported[0] > PERCENT_TRANSPORTED_60) != Chance16(1, 3)) {
+				mul = 1; // Increase production
+			} else {
+				div = 1; // Decrease production
+			}
+		}
+	}
 
-		if (smooth_economy) {
-			closeit = true;
-			for (byte j = 0; j < lengthof(i->produced_cargo); j++) {
-				if (i->produced_cargo[j] == CT_INVALID) continue;
-				uint32 r = Random();
-				int old_prod, new_prod, percent;
-				/* If over 60% is transported, mult is 1, else mult is -1. */
-				int mult = (i->last_month_pct_transported[j] > PERCENT_TRANSPORTED_60) ? 1 : -1;
-
-				new_prod = old_prod = i->production_rate[j];
-
-				/* For industries with only_decrease flags (temperate terrain Oil Wells),
-				 * the multiplier will always be -1 so they will only decrease. */
-				if (only_decrease) {
-					mult = -1;
-				/* For normal industries, if over 60% is transported, 33% chance for decrease.
-				 * Bonus for very high station ratings (over 80%): 16% chance for decrease. */
-				} else if (Chance16I(1, ((i->last_month_pct_transported[j] > PERCENT_TRANSPORTED_80) ? 6 : 3), r)) {
-					mult *= -1;
-				}
+	/* Increase if needed */
+	while (mul-- != 0 && new_prod_level < PRODLEVEL_MAXIMUM) {
+		new_prod_level = min(new_prod_level * 2, PRODLEVEL_MAXIMUM);
+		if (*str == STR_NULL) *str = indspec->production_up_text;
+	}
 
-				/* 4.5% chance for 3-23% (or 1 unit for very low productions) production change,
-				 * determined by mult value. If mult = 1 prod. increases, else (-1) it decreases. */
-				if (Chance16I(1, 22, r >> 16)) {
-					new_prod += mult * (max(((RandomRange(50) + 10) * old_prod) >> 8, 1U));
-				}
+	/* Decrease if needed */
+	while (div-- != 0 && new_prod_level > PRODLEVEL_MINIMUM) {
+		new_prod_level = max(new_prod_level / 2, (int)PRODLEVEL_MINIMUM); // typecast to int required to please MSVC
+		if (*str == STR_NULL) *str = indspec->production_down_text;
+	}
 
-				/* Prevent production to overflow or Oil Rig passengers to be over-"produced" */
-				new_prod = Clamp(new_prod, 1, 255);
+	/* Increase or Decreasing the production level if needed */
+	new_prod_level = ClampU(new_prod_level + increment, PRODLEVEL_MINIMUM, PRODLEVEL_MAXIMUM);
+	return new_prod_level;
+}
 
-				if (((indspec->behaviour & INDUSTRYBEH_BUILT_ONWATER) != 0) && j == 1) {
-					new_prod = Clamp(new_prod, 0, 16);
-				}
+/**
+ * Change industry production or do closure
+ * @param i Industry for which changes are performed
+ * @param monthly true if it's the monthly call, false if it's the random call
+ */
+static void ChangeIndustryProduction(Industry *i, bool monthly)
+{
+	bool closeit = false;
+	StringID str = STR_NULL;
+	bool suppress_message = false;
 
-				/* Do not stop closing the industry when it has the lowest possible production rate */
-				if (new_prod == old_prod && old_prod > 1) {
-					closeit = false;
-					continue;
-				}
+	/* don't use smooth economy for industries using production related callbacks */
+	const IndustrySpec *indspec = GetIndustrySpec(i->type);
+	bool smooth_economy = indspec->UsesSmoothEconomy();
+	if (smooth_economy) {
+		/* decrease or increase */
+		bool only_decrease = (indspec->behaviour & INDUSTRYBEH_DONT_INCR_PROD) && _settings_game.game_creation.landscape == LT_TEMPERATE;
+		closeit = true;
+		for (byte j = 0; j < lengthof(i->produced_cargo); j++) {
+			if (i->produced_cargo[j] == CT_INVALID) continue;
+			uint32 r = Random();
+			int old_prod, new_prod, percent;
+			/* If over 60% is transported, mult is 1, else mult is -1. */
+			int mult = (i->last_month_pct_transported[j] > PERCENT_TRANSPORTED_60) ? 1 : -1;
+
+			new_prod = old_prod = i->production_rate[j];
+
+			/* For industries with only_decrease flags (temperate terrain Oil Wells),
+			 * the multiplier will always be -1 so they will only decrease. */
+			if (only_decrease) {
+				mult = -1;
+			/* For normal industries, if over 60% is transported, 33% chance for decrease.
+			 * Bonus for very high station ratings (over 80%): 16% chance for decrease. */
+			} else if (Chance16I(1, ((i->last_month_pct_transported[j] > PERCENT_TRANSPORTED_80) ? 6 : 3), r)) {
+				mult *= -1;
+			}
 
-				percent = (old_prod == 0) ? 100 : (new_prod * 100 / old_prod - 100);
-				i->production_rate[j] = new_prod;
+			/* 4.5% chance for 3-23% (or 1 unit for very low productions) production change,
+			 * determined by mult value. If mult = 1 prod. increases, else (-1) it decreases. */
+			if (Chance16I(1, 22, r >> 16)) {
+				new_prod += mult * (max(((RandomRange(50) + 10) * old_prod) >> 8, 1U));
+			}
 
-				/* Close the industry when it has the lowest possible production rate */
-				if (new_prod > 1) closeit = false;
+			/* Prevent production to overflow or Oil Rig passengers to be over-"produced" */
+			new_prod = Clamp(new_prod, 1, 255);
 
-				if (abs(percent) >= 10) {
-					ReportNewsProductionChangeIndustry(i, i->produced_cargo[j], percent);
-				}
+			if (((indspec->behaviour & INDUSTRYBEH_BUILT_ONWATER) != 0) && j == 1) {
+				new_prod = Clamp(new_prod, 0, 16);
 			}
-		} else {
-			if (only_decrease || Chance16(1, 3)) {
-				/* If more than 60% transported, 66% chance of increase, else 33% chance of increase */
-				if (!only_decrease && (i->last_month_pct_transported[0] > PERCENT_TRANSPORTED_60) != Chance16(1, 3)) {
-					mul = 1; // Increase production
-				} else {
-					div = 1; // Decrease production
-				}
+
+			/* Do not stop closing the industry when it has the lowest possible production rate */
+			if (new_prod == old_prod && old_prod > 1) {
+				closeit = false;
+				continue;
 			}
-		}
-	}
 
-	if (!callback_enabled && (indspec->life_type & INDUSTRYLIFE_PROCESSING)) {
-		if ( (byte)(_cur_year - i->last_prod_year) >= 5 && Chance16(1, smooth_economy ? 180 : 2)) {
-			closeit = true;
-		}
-	}
+			percent = (old_prod == 0) ? 100 : (new_prod * 100 / old_prod - 100);
+			i->production_rate[j] = new_prod;
 
-	/* Increase if needed */
-	while (mul-- != 0 && i->prod_level < PRODLEVEL_MAXIMUM) {
-		i->prod_level = min(i->prod_level * 2, PRODLEVEL_MAXIMUM);
-		recalculate_multipliers = true;
-		if (str == STR_NULL) str = indspec->production_up_text;
-	}
+			/* Close the industry when it has the lowest possible production rate */
+			if (new_prod > 1) closeit = false;
 
-	/* Decrease if needed */
-	while (div-- != 0 && !closeit) {
-		if (i->prod_level == PRODLEVEL_MINIMUM) {
-			closeit = true;
-		} else {
-			i->prod_level = max(i->prod_level / 2, (int)PRODLEVEL_MINIMUM); // typecast to int required to please MSVC
-			recalculate_multipliers = true;
-			if (str == STR_NULL) str = indspec->production_down_text;
+			if (abs(percent) >= 10) {
+				ReportNewsProductionChangeIndustry(i, i->produced_cargo[j], percent);
+			}
+		}
+
+	} else {
+		byte new_prod_level = ChangeIndustryProductionOriginal(i, monthly, &str, &suppress_message);
+		if (new_prod_level == PRODLEVEL_MINIMUM) closeit = true;
+		if (new_prod_level != i->prod_level) {
+			i->prod_level = new_prod_level;
+			/* Recalculate production_rate
+			 * For non-smooth economy these should always be synchronized with prod_level */
+			i->RecomputeProductionMultipliers();
 		}
 	}
 
-	/* Increase or Decreasing the production level if needed */
-	if (increment != 0) {
-		if (increment < 0 && i->prod_level == PRODLEVEL_MINIMUM) {
+	bool callback_enabled = HasBit(indspec->callback_mask, monthly ? CBM_IND_MONTHLYPROD_CHANGE : CBM_IND_PRODUCTION_CHANGE);
+	if (!callback_enabled && (indspec->life_type & INDUSTRYLIFE_PROCESSING)) {
+		if ( (byte)(_cur_year - i->last_prod_year) >= 5 && Chance16(1, smooth_economy ? 180 : 2)) {
 			closeit = true;
-		} else {
-			i->prod_level = ClampU(i->prod_level + increment, PRODLEVEL_MINIMUM, PRODLEVEL_MAXIMUM);
-			recalculate_multipliers = true;
 		}
 	}
 
-	/* Recalculate production_rate
-	 * For non-smooth economy these should always be synchronized with prod_level */
-	if (recalculate_multipliers) i->RecomputeProductionMultipliers();
-
 	/* Close if needed and allowed */
 	if (closeit && !CheckIndustryCloseDownProtection(i->type)) {
 		i->prod_level = PRODLEVEL_CLOSURE;