diff --git a/imgui.cpp b/imgui.cpp
index bd60d7bc..920168b6 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -777,13 +777,13 @@ const ImWchar* ImStrbolW(const ImWchar* buf_mid_line, const ImWchar* buf_begin)
     return buf_mid_line;
 }
 
-const char* ImStristr(const char* haystack, const char* needle, const char* needle_end)
+const char* ImStristr(const char* haystack, const char* haystack_end, const char* needle, const char* needle_end)
 {
     if (!needle_end)
         needle_end = needle + strlen(needle);
 
     const char un0 = (char)toupper(*needle);
-    while (*haystack)
+    while ((!haystack_end && *haystack) || (haystack_end && haystack < haystack_end))
     {
         if (toupper(*haystack) == un0)
         {
@@ -1326,13 +1326,13 @@ void ImGuiTextFilter::Build()
     }
 }
 
-bool ImGuiTextFilter::PassFilter(const char* val) const
+bool ImGuiTextFilter::PassFilter(const char* text, const char* text_end) const
 {
     if (Filters.empty())
         return true;
 
-    if (val == NULL)
-        val = "";
+    if (text == NULL)
+        text = "";
 
     for (int i = 0; i != Filters.Size; i++)
     {
@@ -1342,13 +1342,13 @@ bool ImGuiTextFilter::PassFilter(const char* val) const
         if (f.front() == '-')
         {
             // Subtract
-            if (ImStristr(val, f.begin()+1, f.end()) != NULL)
+            if (ImStristr(text, text_end, f.begin()+1, f.end()) != NULL)
                 return false;
         }
         else
         {
             // Grep
-            if (ImStristr(val, f.begin(), f.end()) != NULL)
+            if (ImStristr(text, text_end, f.begin(), f.end()) != NULL)
                 return true;
         }
     }
@@ -2635,6 +2635,7 @@ ImVec2 ImGui::CalcTextSize(const char* text, const char* text_end, bool hide_tex
 
 // Helper to calculate coarse clipping of large list of evenly sized items. 
 // NB: Prefer using the ImGuiListClipper higher-level helper if you can!
+// NB: 'items_count' is only used to clamp the result, if you don't know your count you can use INT_MAX
 // If you are displaying thousands of items and you have a random access to the list, you can perform clipping yourself to save on CPU.
 // {
 //    float item_height = ImGui::GetTextLineHeightWithSpacing();
diff --git a/imgui.h b/imgui.h
index e0cf6c66..821e9e34 100644
--- a/imgui.h
+++ b/imgui.h
@@ -851,7 +851,7 @@ struct ImGuiTextFilter
     ImGuiTextFilter(const char* default_filter = "");
     void Clear() { InputBuf[0] = 0; Build(); }
     void Draw(const char* label = "Filter (inc,-exc)", float width = -1.0f);    // Helper calling InputText+Build
-    bool PassFilter(const char* val) const;
+    bool PassFilter(const char* text, const char* text_end = NULL) const;
     bool IsActive() const { return !Filters.empty(); }
     IMGUI_API void Build();
 };
@@ -862,6 +862,7 @@ struct ImGuiTextBuffer
     ImVector<char>      Buf;
 
     ImGuiTextBuffer()   { Buf.push_back(0); }
+    inline char         operator[](int i) { return Buf.Data[i]; }
     const char*         begin() const { return &Buf.front(); }
     const char*         end() const { return &Buf.back(); }      // Buf is zero-terminated, so end() will point on the zero-terminator
     int                 size() const { return Buf.Size-1; }
@@ -962,6 +963,7 @@ struct ImColor
 //    for (int i = clipper.DisplayStart; i < clipper.DisplayEnd; i++) // display only visible items
 //        ImGui::Text("line number %d", i);
 //    clipper.End();
+// NB: 'count' is only used to clamp the result, if you don't know your count you can use INT_MAX
 struct ImGuiListClipper
 {
     float   ItemsHeight;
diff --git a/imgui_internal.h b/imgui_internal.h
index 8512a635..9e09fd30 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -93,7 +93,7 @@ int                 ImStrnicmp(const char* str1, const char* str2, int count);
 char*               ImStrdup(const char* str);
 int                 ImStrlenW(const ImWchar* str);
 const ImWchar*      ImStrbolW(const ImWchar* buf_mid_line, const ImWchar* buf_begin); // Find beginning-of-line
-const char*         ImStristr(const char* haystack, const char* needle, const char* needle_end);
+const char*         ImStristr(const char* haystack, const char* haystack_end, const char* needle, const char* needle_end);
 int                 ImFormatString(char* buf, int buf_size, const char* fmt, ...) IM_PRINTFARGS(3);
 int                 ImFormatStringV(char* buf, int buf_size, const char* fmt, va_list args);