From 64dd829b0adace5921092d2221dd3bb0663bf525 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Mon, 14 Aug 2017 13:48:13 -0700
Subject: [PATCH] Fixed bug 2418 - Structure SDL_gestureTouch leaking

Leonardo

Structure SDL_gestureTouch gets reallocated for every new added gesture but its never freed.

Proposed patch add the function SDL_GestureQuit() that takes care of doing that and gets called when TouchQuit is called.

Gabriel Jacobo

Thanks for the patch. I think it needs a bit of extra work though, looking at the code in SDL_gesture.c , I see that SDL_numGestureTouches only goes up, I think the right fix here involves adding SDL_GestureDelTouch (hooked into SDL_DelTouch) as well as SDL_GestureQuit (as you posted in your patch).
---
 src/events/SDL_gesture.c   | 28 ++++++++++++++++++++++++++++
 src/events/SDL_gesture_c.h |  3 +++
 src/events/SDL_touch.c     |  4 ++++
 3 files changed, 35 insertions(+)

diff --git a/src/events/SDL_gesture.c b/src/events/SDL_gesture.c
index 8b21066b2..e8477acbb 100644
--- a/src/events/SDL_gesture.c
+++ b/src/events/SDL_gesture.c
@@ -101,6 +101,12 @@ int SDL_RecordGesture(SDL_TouchID touchId)
     return (touchId < 0);
 }
 
+void SDL_GestureQuit()
+{
+    SDL_free(SDL_gestureTouch);
+    SDL_gestureTouch = NULL;
+}
+
 static unsigned long SDL_HashDollar(SDL_FloatPoint* points)
 {
     unsigned long hash = 5381;
@@ -457,6 +463,28 @@ int SDL_GestureAddTouch(SDL_TouchID touchId)
     return 0;
 }
 
+int SDL_GestureDelTouch(SDL_TouchID touchId)
+{
+    int i;
+    for (i = 0; i < SDL_numGestureTouches; i++) {
+        if (SDL_gestureTouch[i].id == touchId) {
+            break;
+        }
+    }
+
+    if (i == SDL_numGestureTouches) {
+        /* not found */
+        return -1;
+    }
+
+    SDL_free(SDL_gestureTouch[i].dollarTemplate);
+    SDL_zero(SDL_gestureTouch[i]);
+
+    SDL_numGestureTouches--;
+    SDL_gestureTouch[i] = SDL_gestureTouch[SDL_numGestureTouches];
+    return 0;
+}
+
 static SDL_GestureTouch * SDL_GetGestureTouch(SDL_TouchID id)
 {
     int i;
diff --git a/src/events/SDL_gesture_c.h b/src/events/SDL_gesture_c.h
index bce812b9e..ab588b04e 100644
--- a/src/events/SDL_gesture_c.h
+++ b/src/events/SDL_gesture_c.h
@@ -24,9 +24,12 @@
 #define SDL_gesture_c_h_
 
 extern int SDL_GestureAddTouch(SDL_TouchID touchId);
+extern int SDL_GestureDelTouch(SDL_TouchID touchId);
 
 extern void SDL_GestureProcessEvent(SDL_Event* event);
 
+extern void SDL_GestureQuit(void);
+
 #endif /* SDL_gesture_c_h_ */
 
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/events/SDL_touch.c b/src/events/SDL_touch.c
index 92e76f2e4..39a765a78 100644
--- a/src/events/SDL_touch.c
+++ b/src/events/SDL_touch.c
@@ -352,6 +352,9 @@ SDL_DelTouch(SDL_TouchID id)
 
     SDL_num_touch--;
     SDL_touchDevices[index] = SDL_touchDevices[SDL_num_touch];
+
+    /* Delete this touch device for gestures */
+    SDL_GestureDelTouch(id);
 }
 
 void
@@ -366,6 +369,7 @@ SDL_TouchQuit(void)
 
     SDL_free(SDL_touchDevices);
     SDL_touchDevices = NULL;
+    SDL_GestureQuit();
 }
 
 /* vi: set ts=4 sw=4 expandtab: */