From 3897c49e30920cb6bd40c2f3614b9f3346650943 Mon Sep 17 00:00:00 2001
From: Allofich <rickywd@gmail.com>
Date: Sat, 18 Feb 2017 01:38:21 +0900
Subject: [PATCH] Fix loading 0-duration Follow and Escort packages

(Fixes #3755)
---
 apps/openmw/mwmechanics/aiescort.cpp | 21 +++++++++++----------
 apps/openmw/mwmechanics/aifollow.cpp | 23 ++++++++++++-----------
 2 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/apps/openmw/mwmechanics/aiescort.cpp b/apps/openmw/mwmechanics/aiescort.cpp
index f655fee85..4c9b5fd4f 100644
--- a/apps/openmw/mwmechanics/aiescort.cpp
+++ b/apps/openmw/mwmechanics/aiescort.cpp
@@ -45,8 +45,8 @@ namespace MWMechanics
         , mCellY(std::numeric_limits<int>::max())
     {
         // mDuration isn't saved in the save file, so just giving it "1" for now if the package has a duration.
-        // The exact value of mDuration only matters for repeating packages 
-        if (mRemainingDuration != 0)
+        // The exact value of mDuration only matters for repeating packages.
+        if (mRemainingDuration > 0) // Previously mRemainingDuration could be negative even when mDuration was 0. Checking for > 0 should fix old saves.
             mDuration = 1;
         else
             mDuration = 0;
@@ -62,7 +62,7 @@ namespace MWMechanics
     {
         // If AiEscort has ran for as long or longer then the duration specified
         // and the duration is not infinite, the package is complete.
-        if(mDuration > 0)
+        if (mDuration > 0)
         {
             mRemainingDuration -= ((duration*MWBase::Environment::get().getWorld()->getTimeScaleFactor()) / 3600);
             if (mRemainingDuration <= 0)
@@ -90,13 +90,13 @@ namespace MWMechanics
             (differenceBetween[0] * differenceBetween[0]) + (differenceBetween[1] * differenceBetween[1]) + (differenceBetween[2] *
                 differenceBetween[2]);
 
-        if(distanceBetweenResult <= mMaxDist * mMaxDist)
+        if (distanceBetweenResult <= mMaxDist * mMaxDist)
         {
             ESM::Pathgrid::Point point(static_cast<int>(mX), static_cast<int>(mY), static_cast<int>(mZ));
             point.mAutogenerated = 0;
             point.mConnectionNum = 0;
             point.mUnknown = 0;
-            if(pathTo(actor,point,duration)) //Returns true on path complete
+            if (pathTo(actor,point,duration)) //Returns true on path complete
             {
                 mRemainingDuration = mDuration;
                 return true;
@@ -140,10 +140,11 @@ namespace MWMechanics
         sequence.mPackages.push_back(package);
     }
 
-void AiEscort::fastForward(const MWWorld::Ptr& actor, AiState &state)
-{
-    // Update duration counter
-    mRemainingDuration--;
-}
+    void AiEscort::fastForward(const MWWorld::Ptr& actor, AiState &state)
+    {
+        // Update duration counter if this package has a duration
+        if (mDuration > 0)
+            mRemainingDuration--;
+    }
 }
 
diff --git a/apps/openmw/mwmechanics/aifollow.cpp b/apps/openmw/mwmechanics/aifollow.cpp
index fb080d046..9d79d4ba9 100644
--- a/apps/openmw/mwmechanics/aifollow.cpp
+++ b/apps/openmw/mwmechanics/aifollow.cpp
@@ -52,9 +52,9 @@ AiFollow::AiFollow(const ESM::AiSequence::AiFollow *follow)
     , mActorRefId(follow->mTargetId), mActorId(-1)
     , mCellId(follow->mCellId), mActive(follow->mActive), mFollowIndex(mFollowIndexCounter++)
 {
-// mDuration isn't saved in the save file, so just giving it "1" for now if the package has a duration.
-// The exact value of mDuration only matters for repeating packages
-    if (mRemainingDuration != 0)
+// mDuration isn't saved in the save file, so just giving it "1" for now if the package had a duration.
+// The exact value of mDuration only matters for repeating packages.
+    if (mRemainingDuration > 0) // Previously mRemainingDuration could be negative even when mDuration was 0. Checking for > 0 should fix old saves.
        mDuration = 1;
     else
        mDuration = 0;
@@ -104,10 +104,10 @@ bool AiFollow::execute (const MWWorld::Ptr& actor, CharacterController& characte
         ++i;
     }
 
-    if(!mAlwaysFollow) //Update if you only follow for a bit
+    if (!mAlwaysFollow) //Update if you only follow for a bit
     {
          //Check if we've run out of time
-        if (mDuration != 0)
+        if (mDuration > 0)
         {
             mRemainingDuration -= ((duration*MWBase::Environment::get().getWorld()->getTimeScaleFactor()) / 3600);
             if (mRemainingDuration <= 0)
@@ -117,18 +117,18 @@ bool AiFollow::execute (const MWWorld::Ptr& actor, CharacterController& characte
             }
         }
 
-        if((pos.pos[0]-mX)*(pos.pos[0]-mX) +
+        if ((pos.pos[0]-mX)*(pos.pos[0]-mX) +
             (pos.pos[1]-mY)*(pos.pos[1]-mY) +
             (pos.pos[2]-mZ)*(pos.pos[2]-mZ) < followDistance*followDistance) //Close-ish to final position
         {
-            if(actor.getCell()->isExterior()) //Outside?
+            if (actor.getCell()->isExterior()) //Outside?
             {
-                if(mCellId == "") //No cell to travel to
+                if (mCellId == "") //No cell to travel to
                     return true;
             }
             else
             {
-                if(mCellId == actor.getCell()->getCell()->mName) //Cell to travel to
+                if (mCellId == actor.getCell()->getCell()->mName) //Cell to travel to
                     return true;
             }
         }
@@ -228,8 +228,9 @@ int AiFollow::getFollowIndex() const
 
 void AiFollow::fastForward(const MWWorld::Ptr& actor, AiState &state)
 {
-    // Update duration counter
-    mRemainingDuration--;
+    // Update duration counter if this package has a duration
+    if (mDuration > 0)
+        mRemainingDuration--;
 }
 
 }