InputTextMultiline: InputTextMultiline: fixed an issue calculating lines count when active.

Amend 4252275

Author: ocornut

docs/CHANGELOG.txt

@@ -84,7 +84,8 @@ Other Changes:
   - Fixed selection highlight Y1 offset being very slightly off (since 1.92.3). (#9311) [@v-ein]
   - InputTextMultiline: fixed an issue introduced in 1.92.3 where line count calculated
     for vertical scrollbar range would be +1 when the widget is inactive, word-wrap is
-    disabled and the text buffer ends with '\n'.
+    disabled and the text buffer ends with '\n'. Fixed a similar issue related to clipping
+    large amount of text.
 - Style:
   - Border sizes are now scaled (and rounded) by ScaleAllSizes().
   - When using large values with ScallAllSizes(), the following items thickness

imgui.cpp

@@ -5565,7 +5565,7 @@ void ImGui::NewFrame()
     // As a result, custom widget using ButtonBehavior() _without_ ItemAdd() need to call KeepAliveID() themselves.
     if (g.ActiveId != 0 && g.ActiveIdIsAlive != g.ActiveId && g.ActiveIdPreviousFrame == g.ActiveId)
     {
-        IMGUI_DEBUG_LOG_ACTIVEID("NewFrame(): ClearActiveID() because it isn't marked alive anymore!\n");
+        IMGUI_DEBUG_LOG_ACTIVEID("NewFrame(): ClearActiveID() 0x%08X because it isn't marked alive anymore!\n", g.ActiveId);
         ClearActiveID();
     }
 

imgui_widgets.cpp

@@ -4629,11 +4629,8 @@ static int InputTextLineIndexBuild(ImGuiInputTextFlags flags, ImGuiTextIndex* li
         line_index->Offsets.push_back(0);
         size++;
     }
-    if (buf_end > buf && buf_end[-1] == '\n' && size <= max_output_buffer_size && !trailing_line_already_counted)
-    {
+    if (buf_end > buf && buf_end[-1] == '\n' && !trailing_line_already_counted && size++ <= max_output_buffer_size)
         line_index->Offsets.push_back((int)(buf_end - buf));
-        size++;
-    }
     return size;
 }