1 files changed, 48 insertions, 6 deletions

diff --git a/indra/llui/llaccordionctrltab.cpp b/indra/llui/llaccordionctrltab.cpp
index ac66525030..828bfb289b 100644
--- a/indra/llui/llaccordionctrltab.cpp
+++ b/indra/llui/llaccordionctrltab.cpp
@@ -248,10 +248,22 @@ void LLAccordionCtrlTab::LLAccordionCtrlTabHeader::draw()
 void LLAccordionCtrlTab::LLAccordionCtrlTabHeader::reshape(S32 width, S32 height, bool called_from_parent /* = true */)
 {
     S32 header_height = mHeaderTextbox->getTextPixelHeight();
+    LLRect old_header_rect = mHeaderTextbox->getRect();
 
     LLRect textboxRect(HEADER_TEXT_LEFT_OFFSET, (height + header_height) / 2, width, (height - header_height) / 2);
-    mHeaderTextbox->reshape(textboxRect.getWidth(), textboxRect.getHeight());
-    mHeaderTextbox->setRect(textboxRect);
+    if (old_header_rect.getHeight() != textboxRect.getHeight()
+        || old_header_rect.mLeft != textboxRect.mLeft
+        || old_header_rect.mTop != textboxRect.mTop
+        || old_header_rect.getWidth() > textboxRect.getWidth() // reducing header's width
+        || (old_header_rect.getWidth() < textboxRect.getWidth() && old_header_rect.getWidth() < mHeaderTextbox->getTextPixelWidth()))
+    {
+        // Expensive text reflow
+        // Update if position or height changes
+        // Update if width reduces
+        // But do not update if text already fits and width increases (arguably LLTextBox::reshape should be smarter, not Accordion)
+        mHeaderTextbox->reshape(textboxRect.getWidth(), textboxRect.getHeight());
+        mHeaderTextbox->setRect(textboxRect);
+    }
 
     if (mHeaderTextbox->getTextPixelWidth() > mHeaderTextbox->getRect().getWidth())
     {
@@ -416,8 +428,11 @@ void LLAccordionCtrlTab::reshape(S32 width, S32 height, bool called_from_parent
     LLRect headerRect;
 
     headerRect.setLeftTopAndSize(0, height, width, HEADER_HEIGHT);
-    mHeader->setRect(headerRect);
-    mHeader->reshape(headerRect.getWidth(), headerRect.getHeight());
+    if (mHeader->getRect() != headerRect)
+    {
+        mHeader->setRect(headerRect);
+        mHeader->reshape(headerRect.getWidth(), headerRect.getHeight());
+    }
 
     if (!mDisplayChildren)
         return;
@@ -464,7 +479,34 @@ void LLAccordionCtrlTab::onUpdateScrollToChild(const LLUICtrl *cntrl)
         // Translate to parent coordinatess to check if we are in visible rectangle
         rect.translate(getRect().mLeft, getRect().mBottom);
 
-        if (!getRect().contains(rect))
+        bool needs_to_scroll = false;
+        const LLRect &acc_rect = getRect();
+        if (!acc_rect.contains(rect))
+        {
+            if (acc_rect.mTop < rect.mBottom || acc_rect.mBottom > rect.mTop)
+            {
+                // Content fully not in view
+                needs_to_scroll = true;
+            }
+            else if (acc_rect.getHeight() >= rect.getHeight())
+            {
+                // Content can be displayed fully, but only partially in view
+                needs_to_scroll = true;
+            }
+            else if (acc_rect.mTop <= rect.mTop || acc_rect.mBottom >= rect.mBottom)
+            {
+                // Intersects, but too big to be displayed fully
+                S32 covered_height = acc_rect.mTop > rect.mTop ? rect.mTop - acc_rect.mBottom : acc_rect.mTop - rect.mBottom;
+                constexpr F32 covered_ratio = 0.7f;
+                if (covered_height < covered_ratio * acc_rect.getHeight())
+                {
+                    // Try to show bigger portion of the content
+                    needs_to_scroll = true;
+                }
+            }
+            // else too big and in the middle of the view as is
+        }
+        if (needs_to_scroll)
         {
             // for accordition's scroll, height is in pixels
             // Back to local coords and calculate position for scroller
@@ -932,7 +974,7 @@ void LLAccordionCtrlTab::adjustContainerPanel(const LLRect& child_rect)
         show_hide_scrollbar(child_rect);
         updateLayout(child_rect);
     }
-    else
+    else if (mContainerPanel->getRect() != child_rect)
     {
         mContainerPanel->reshape(child_rect.getWidth(), child_rect.getHeight());
         mContainerPanel->setRect(child_rect);