# HG changeset patch
# User fonsinchen <fonsinchen@openttd.org>
# Date 2014-04-08 19:28:14
# Node ID 95eabab86f13f69276d0de27c5190f0092cf53cc
# Parent  0c85f6f7d752482fa602f0b87584374d9e322d08

(svn r26448) -Fix [FS#5970]: Avoid division by 0 when scaling flow values.

diff --git a/src/linkgraph/flowmapper.cpp b/src/linkgraph/flowmapper.cpp
--- a/src/linkgraph/flowmapper.cpp
+++ b/src/linkgraph/flowmapper.cpp
@@ -49,8 +49,10 @@ void FlowMapper::Run(LinkGraphJob &job) 
 		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/station_cmd.cpp b/src/station_cmd.cpp
--- 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) {