From 5fd1ac47adc11be2ec24fdd03fd75b1f50b95726 Mon Sep 17 00:00:00 2001
From: frosch <frosch@openttd.org>
Date: Sun, 13 Apr 2014 10:52:19 +0000
Subject: [PATCH] (svn r26461) [1.4] -Backport from trunk: - Fix: Avoid
 division by 0 when scaling flow values [FS#5970] (r26448) - Feature: Draw
 links to match _settings_game.vehicle.road_side [FS#5961] (r26445) - Change:
 Use pkg-config for libpng as well (r26435, r26433, r26432) - Feature: Load
 button for heightmap list [FS#5953] (r26428)

---
 src/linkgraph/flowmapper.cpp    | 6 ++++--
 src/linkgraph/linkgraph_gui.cpp | 5 +++--
 src/station_cmd.cpp             | 2 ++
 src/widgets/story_widget.h      | 2 +-
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/linkgraph/flowmapper.cpp b/src/linkgraph/flowmapper.cpp
index 79e0f09f3f..3daab44142 100644
--- a/src/linkgraph/flowmapper.cpp
+++ b/src/linkgraph/flowmapper.cpp
@@ -49,8 +49,10 @@ void FlowMapper::Run(LinkGraphJob &job) const
 		FlowStatMap &flows = node.Flows();
 		flows.FinalizeLocalConsumption(node.Station());
 		if (this->scale) {
-			/* Scale by time the graph has been running without being compressed. */
-			uint runtime = job.JoinDate() - job.Settings().recalc_time - job.LastCompression();
+			/* Scale by time the graph has been running without being compressed. Add 1 to avoid
+			 * division by 0 if spawn date == last compression date. This matches
+			 * LinkGraph::Monthly(). */
+			uint runtime = job.JoinDate() - job.Settings().recalc_time - job.LastCompression() + 1;
 			for (FlowStatMap::iterator i = flows.begin(); i != flows.end(); ++i) {
 				i->second.ScaleToMonthly(runtime);
 			}
diff --git a/src/linkgraph/linkgraph_gui.cpp b/src/linkgraph/linkgraph_gui.cpp
index 9889ad87ae..093d7ab4d1 100644
--- a/src/linkgraph/linkgraph_gui.cpp
+++ b/src/linkgraph/linkgraph_gui.cpp
@@ -220,11 +220,12 @@ void LinkGraphOverlay::DrawContent(Point pta, Point ptb, const LinkProperties &c
 
 	/* Move line a bit 90° against its dominant direction to prevent it from
 	 * being hidden below the grey line. */
+	int side = _settings_game.vehicle.road_side ? 1 : -1;
 	if (abs(pta.x - ptb.x) < abs(pta.y - ptb.y)) {
-		int offset_x = (pta.y > ptb.y ? 1 : -1) * this->scale;
+		int offset_x = (pta.y > ptb.y ? 1 : -1) * side * this->scale;
 		GfxDrawLine(pta.x + offset_x, pta.y, ptb.x + offset_x, ptb.y, colour, this->scale, dash);
 	} else {
-		int offset_y = (pta.x < ptb.x ? 1 : -1) * this->scale;
+		int offset_y = (pta.x < ptb.x ? 1 : -1) * side * this->scale;
 		GfxDrawLine(pta.x, pta.y + offset_y, ptb.x, ptb.y + offset_y, colour, this->scale, dash);
 	}
 
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 55b6fae14d..d637d83c38 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -4314,9 +4314,11 @@ void FlowStat::ReleaseShare(StationID st)
 /**
  * Scale all shares from link graph's runtime to monthly values.
  * @param runtime Time the link graph has been running without compression.
+ * @pre runtime must be greater than 0 as we don't want infinite flow values.
  */
 void FlowStat::ScaleToMonthly(uint runtime)
 {
+	assert(runtime > 0);
 	SharesMap new_shares;
 	uint share = 0;
 	for (SharesMap::iterator i = this->shares.begin(); i != this->shares.end(); ++i) {
diff --git a/src/widgets/story_widget.h b/src/widgets/story_widget.h
index c3f279444d..139b6d2d6b 100644
--- a/src/widgets/story_widget.h
+++ b/src/widgets/story_widget.h
@@ -23,4 +23,4 @@ enum StoryBookWidgets {
 	WID_SB_NEXT_PAGE, ///< Next button.
 };
 
-#endif /* WIDGETS_STORY_WIDGET_H */
\ No newline at end of file
+#endif /* WIDGETS_STORY_WIDGET_H */