Core/PathGenerator: Fix path generator returning shortcuts when start and end are on the same polygon (#24083)

* Core/PathGenerator: Fix path generator returning shortcuts when start and end are on the same polygon

Second try of handling paths on same poly in a better way than just building a shortcut

* Fix movement generators using paths with start/end positions far from mmap polygons

* Include flag PATHFIND_FARFROMPOLY even with a normal path if start or end were far away from mmap poly

(cherry picked from commit 67d9d04d63cc74196059646b2e57f50a4a4fd2ca)

5 files changed, 33 insertions, 14 deletions

diff --git a/src/server/game/Movement/MovementGenerators/ConfusedMovementGenerator.cpp b/src/server/game/Movement/MovementGenerators/ConfusedMovementGenerator.cpp
index 9296cddc242..dd6e3708d68 100755
--- a/src/server/game/Movement/MovementGenerators/ConfusedMovementGenerator.cpp
+++ b/src/server/game/Movement/MovementGenerators/ConfusedMovementGenerator.cpp
@@ -107,7 +107,9 @@ bool ConfusedMovementGenerator<T>::DoUpdate(T* owner, uint32 diff)
         }
 
         bool result = _path->CalculatePath(destination.GetPositionX(), destination.GetPositionY(), destination.GetPositionZ());
-        if (!result || (_path->GetPathType() & PATHFIND_NOPATH) || (_path->GetPathType() & PATHFIND_SHORTCUT))
+        if (!result || (_path->GetPathType() & PATHFIND_NOPATH)
+                    || (_path->GetPathType() & PATHFIND_SHORTCUT)
+                    || (_path->GetPathType() & PATHFIND_FARFROMPOLY))
         {
             _timer.Reset(100);
             return true;
diff --git a/src/server/game/Movement/MovementGenerators/FleeingMovementGenerator.cpp b/src/server/game/Movement/MovementGenerators/FleeingMovementGenerator.cpp
index 26aaf495c2e..39f559394ee 100644
--- a/src/server/game/Movement/MovementGenerators/FleeingMovementGenerator.cpp
+++ b/src/server/game/Movement/MovementGenerators/FleeingMovementGenerator.cpp
@@ -165,7 +165,9 @@ void FleeingMovementGenerator<T>::SetTargetLocation(T* owner)
     }
 
     bool result = _path->CalculatePath(destination.GetPositionX(), destination.GetPositionY(), destination.GetPositionZ());
-    if (!result || (_path->GetPathType() & PATHFIND_NOPATH) || (_path->GetPathType() & PATHFIND_SHORTCUT))
+    if (!result || (_path->GetPathType() & PATHFIND_NOPATH)
+                || (_path->GetPathType() & PATHFIND_SHORTCUT)
+                || (_path->GetPathType() & PATHFIND_FARFROMPOLY))
     {
         _timer.Reset(100);
         return;
diff --git a/src/server/game/Movement/MovementGenerators/RandomMovementGenerator.cpp b/src/server/game/Movement/MovementGenerators/RandomMovementGenerator.cpp
index cd32124df2d..630b03606f0 100644
--- a/src/server/game/Movement/MovementGenerators/RandomMovementGenerator.cpp
+++ b/src/server/game/Movement/MovementGenerators/RandomMovementGenerator.cpp
@@ -140,7 +140,9 @@ void RandomMovementGenerator<Creature>::SetRandomLocation(Creature* owner)
     }
 
     bool result = _path->CalculatePath(position.GetPositionX(), position.GetPositionY(), position.GetPositionZ());
-    if (!result || (_path->GetPathType() & PATHFIND_NOPATH) || (_path->GetPathType() & PATHFIND_SHORTCUT))
+    if (!result || (_path->GetPathType() & PATHFIND_NOPATH)
+                || (_path->GetPathType() & PATHFIND_SHORTCUT)
+                || (_path->GetPathType() & PATHFIND_FARFROMPOLY))
     {
         _timer.Reset(100);
         return;
diff --git a/src/server/game/Movement/PathGenerator.cpp b/src/server/game/Movement/PathGenerator.cpp
index 711e57eb1b5..ac46a8963c8 100644
--- a/src/server/game/Movement/PathGenerator.cpp
+++ b/src/server/game/Movement/PathGenerator.cpp
@@ -226,7 +226,7 @@ void PathGenerator::BuildPolyPath(G3D::Vector3 const& startPos, G3D::Vector3 con
         if (buildShotrcut)
         {
             BuildShortcut();
-            _type = PathType(PATHFIND_NORMAL | PATHFIND_NOT_USING_PATH);
+            _type = PathType(PATHFIND_NORMAL | PATHFIND_NOT_USING_PATH | PATHFIND_FARFROMPOLY);
             return;
         }
         else
@@ -239,7 +239,7 @@ void PathGenerator::BuildPolyPath(G3D::Vector3 const& startPos, G3D::Vector3 con
                 SetActualEndPosition(G3D::Vector3(endPoint[2], endPoint[0], endPoint[1]));
             }
 
-            _type = PATHFIND_INCOMPLETE;
+            _type = PathType(PATHFIND_INCOMPLETE | PATHFIND_FARFROMPOLY);
         }
     }
 
@@ -250,14 +250,12 @@ void PathGenerator::BuildPolyPath(G3D::Vector3 const& startPos, G3D::Vector3 con
     if (startPoly == endPoly)
     {
         TC_LOG_DEBUG("maps.mmaps", "++ BuildPolyPath :: (startPoly == endPoly)");
-
-        BuildShortcut();
-
         _pathPolyRefs[0] = startPoly;
         _polyLength = 1;
 
-        _type = farFromPoly ? PATHFIND_INCOMPLETE : PATHFIND_NORMAL;
-        TC_LOG_DEBUG("maps.mmaps", "++ BuildPolyPath :: path type %d", _type);
+        _type = farFromPoly ? PathType(PATHFIND_INCOMPLETE | PATHFIND_FARFROMPOLY) : PATHFIND_NORMAL;
+
+        BuildPointPath(startPoint, endPoint);
         return;
     }
 
@@ -468,6 +466,9 @@ void PathGenerator::BuildPolyPath(G3D::Vector3 const& startPos, G3D::Vector3 con
     else
         _type = PATHFIND_INCOMPLETE;
 
+    if (farFromPoly)
+        _type = PathType(_type | PATHFIND_FARFROMPOLY);
+
     // generate the point-path out of our up-to-date poly-path
     BuildPointPath(startPoint, endPoint);
 }
@@ -774,11 +775,22 @@ dtStatus PathGenerator::FindSmoothPath(float const* startPos, float const* endPo
     uint32 npolys = polyPathSize;
 
     float iterPos[VERTEX_SIZE], targetPos[VERTEX_SIZE];
-    if (dtStatusFailed(_navMeshQuery->closestPointOnPolyBoundary(polys[0], startPos, iterPos)))
-        return DT_FAILURE;
 
-    if (dtStatusFailed(_navMeshQuery->closestPointOnPolyBoundary(polys[npolys-1], endPos, targetPos)))
-        return DT_FAILURE;
+    if (polyPathSize > 1)
+    {
+        // Pick the closest poitns on poly border
+        if (dtStatusFailed(_navMeshQuery->closestPointOnPolyBoundary(polys[0], startPos, iterPos)))
+            return DT_FAILURE;
+
+        if (dtStatusFailed(_navMeshQuery->closestPointOnPolyBoundary(polys[npolys - 1], endPos, targetPos)))
+            return DT_FAILURE;
+    }
+    else
+    {
+        // Case where the path is on the same poly
+        dtVcopy(iterPos, startPos);
+        dtVcopy(targetPos, endPos);
+    }
 
     dtVcopy(&smoothPath[nsmoothPath*VERTEX_SIZE], iterPos);
     nsmoothPath++;
diff --git a/src/server/game/Movement/PathGenerator.h b/src/server/game/Movement/PathGenerator.h
index 730efdcc995..3a9c260684f 100644
--- a/src/server/game/Movement/PathGenerator.h
+++ b/src/server/game/Movement/PathGenerator.h
@@ -47,6 +47,7 @@ enum PathType
     PATHFIND_NOPATH         = 0x08,   // no valid path at all or error in generating one
     PATHFIND_NOT_USING_PATH = 0x10,   // used when we are either flying/swiming or on map w/o mmaps
     PATHFIND_SHORT          = 0x20,   // path is longer or equal to its limited path length
+    PATHFIND_FARFROMPOLY    = 0x40,   // start of end positions are far from the mmap poligon
 };
 
 class TC_GAME_API PathGenerator