Don't perform a hit test outside the page's bounds

CHANGELOG.md

@@ -115,6 +115,7 @@
     Bug #5906: Sunglare doesn't work with Mesa drivers and AMD GPUs
     Bug #5912: ImprovedBound mod doesn't work
     Bug #5914: BM: The Swimmer can't reach destination
+    Bug #5923: Clicking on empty spaces between journal entries might show random topics
     Bug #5934: AddItem command doesn't accept negative values
     Feature #390: 3rd person look "over the shoulder"
     Feature #832: OpenMW-CS: Handle deleted references

apps/openmw/mwgui/bookpage.cpp

@@ -1,5 +1,7 @@
 #include "bookpage.hpp"
 
+#include <optional>
+
 #include "MyGUI_RenderItem.h"
 #include "MyGUI_RenderManager.h"
 #include "MyGUI_TextureUtility.h"
@@ -894,6 +896,27 @@ protected:
        return mIsPageReset || (mPage != page);
     }
 
+    std::optional<MyGUI::IntPoint> getAdjustedPos(int left, int top, bool move = false)
+    {
+        if (!mBook)
+            return {};
+
+        if (mPage >= mBook->mPages.size())
+            return {};
+
+        MyGUI::IntPoint pos (left, top);
+#if MYGUI_VERSION < MYGUI_DEFINE_VERSION(3,2,3)
+        // work around inconsistency in MyGUI where the mouse press coordinates aren't
+        // transformed by the current Layer (even though mouse *move* events are).
+        if(!move)
+            pos = mNode->getLayer()->getPosition(left, top);
+#endif
+        pos.left -= mCroppedParent->getAbsoluteLeft ();
+        pos.top  -= mCroppedParent->getAbsoluteTop  ();
+        pos.top += mViewTop;
+        return pos;
+    }
+
 public:
 
     typedef TypesetBookImpl::StyleImpl Style;
@@ -952,16 +975,10 @@ public:
 
     void onMouseMove (int left, int top)
     {
-        if (!mBook)
-            return;
-
-        if (mPage >= mBook->mPages.size())
-            return;
-
-        left -= mCroppedParent->getAbsoluteLeft ();
-        top  -= mCroppedParent->getAbsoluteTop  ();
-
-        Style * hit = mBook->hitTestWithMargin (left, mViewTop + top);
+        Style * hit = nullptr;
+        if(auto pos = getAdjustedPos(left, top, true))
+            if(pos->top <= mViewBottom)
+                hit = mBook->hitTestWithMargin (pos->left, pos->top);
 
         if (mLastDown == MyGUI::MouseButton::None)
         {
@@ -991,24 +1008,11 @@ public:
 
     void onMouseButtonPressed (int left, int top, MyGUI::MouseButton id)
     {
-        if (!mBook)
-            return;
+        auto pos = getAdjustedPos(left, top);
 
-        if (mPage >= mBook->mPages.size())
-            return;
-
-        // work around inconsistency in MyGUI where the mouse press coordinates aren't
-        // transformed by the current Layer (even though mouse *move* events are).
-        MyGUI::IntPoint pos (left, top);
-#if MYGUI_VERSION < MYGUI_DEFINE_VERSION(3,2,3)
-        pos = mNode->getLayer()->getPosition(left, top);
-#endif
-        pos.left -= mCroppedParent->getAbsoluteLeft ();
-        pos.top  -= mCroppedParent->getAbsoluteTop  ();
-
-        if (mLastDown == MyGUI::MouseButton::None)
+        if (pos && mLastDown == MyGUI::MouseButton::None)
         {
-            mFocusItem = mBook->hitTestWithMargin (pos.left, mViewTop + pos.top);
+            mFocusItem = pos->top <= mViewBottom ? mBook->hitTestWithMargin (pos->left, pos->top) : nullptr;
             mItemActive = true;
 
             dirtyFocusItem ();
@@ -1019,25 +1023,11 @@ public:
 
     void onMouseButtonReleased(int left, int top, MyGUI::MouseButton id)
     {
-        if (!mBook)
-            return;
-
-        if (mPage >= mBook->mPages.size())
-            return;
-
-        // work around inconsistency in MyGUI where the mouse release coordinates aren't
-        // transformed by the current Layer (even though mouse *move* events are).
-        MyGUI::IntPoint pos (left, top);
-#if MYGUI_VERSION < MYGUI_DEFINE_VERSION(3,2,3)
-        pos = mNode->getLayer()->getPosition(left, top);
-#endif
-
-        pos.left -= mCroppedParent->getAbsoluteLeft ();
-        pos.top  -= mCroppedParent->getAbsoluteTop  ();
+        auto pos = getAdjustedPos(left, top);
 
-        if (mLastDown == id)
+        if (pos && mLastDown == id)
         {
-            Style * item = mBook->hitTestWithMargin (pos.left, mViewTop + pos.top);
+            Style * item = pos->top <= mViewBottom ? mBook->hitTestWithMargin (pos->left, pos->top) : nullptr;
 
             bool clicked = mFocusItem == item;