diff --git a/3rdparty/ocornut-imgui/imgui.cpp b/3rdparty/ocornut-imgui/imgui.cpp
index 1f1aaedc9..5db642f08 100644
--- a/3rdparty/ocornut-imgui/imgui.cpp
+++ b/3rdparty/ocornut-imgui/imgui.cpp
@@ -908,7 +908,7 @@ int ImTextCharFromUtf8(unsigned int* out_char, const char* in_text, const char*
     if ((*str & 0xe0) == 0xc0)
     {
         *out_char = 0xFFFD; // will be invalid but not end of string
-        if (in_text_end && in_text_end - (const char*)str < 2) return 0;
+        if (in_text_end && in_text_end - (const char*)str < 2) return 1;
         if (*str < 0xc2) return 2;
         c = (unsigned int)((*str++ & 0x1f) << 6);
         if ((*str & 0xc0) != 0x80) return 2;
@@ -919,7 +919,7 @@ int ImTextCharFromUtf8(unsigned int* out_char, const char* in_text, const char*
     if ((*str & 0xf0) == 0xe0)
     {
         *out_char = 0xFFFD; // will be invalid but not end of string
-        if (in_text_end && in_text_end - (const char*)str < 3) return 0; 
+        if (in_text_end && in_text_end - (const char*)str < 3) return 1; 
         if (*str == 0xe0 && (str[1] < 0xa0 || str[1] > 0xbf)) return 3;
         if (*str == 0xed && str[1] > 0x9f) return 3; // str[1] < 0x80 is checked below
         c = (unsigned int)((*str++ & 0x0f) << 12);
@@ -933,7 +933,7 @@ int ImTextCharFromUtf8(unsigned int* out_char, const char* in_text, const char*
     if ((*str & 0xf8) == 0xf0)
     {
         *out_char = 0xFFFD; // will be invalid but not end of string
-        if (in_text_end && in_text_end - (const char*)str < 4) return 0;
+        if (in_text_end && in_text_end - (const char*)str < 4) return 1;
         if (*str > 0xf4) return 4;
         if (*str == 0xf0 && (str[1] < 0x90 || str[1] > 0xbf)) return 4;
         if (*str == 0xf4 && str[1] > 0x8f) return 4; // str[1] < 0x80 is checked below
@@ -7217,7 +7217,8 @@ bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2
         if (g.IO.InputCharacters[0])
         {
             // Process text input (before we check for Return because using some IME will effectively send a Return?)
-            if (!is_ctrl_down && is_editable)
+            // We ignore CTRL inputs, but need to allow CTRL+ALT as some keyboards (e.g. German) use AltGR - which is Alt+Ctrl - to input certain characters.
+            if (!(is_ctrl_down && !is_alt_down) && is_editable)
             {
                 for (int n = 0; n < IM_ARRAYSIZE(g.IO.InputCharacters) && g.IO.InputCharacters[n]; n++)
                     if (unsigned int c = (unsigned int)g.IO.InputCharacters[n])
diff --git a/3rdparty/ocornut-imgui/imgui.h b/3rdparty/ocornut-imgui/imgui.h
index 9d7c88a04..6f504ed62 100644
--- a/3rdparty/ocornut-imgui/imgui.h
+++ b/3rdparty/ocornut-imgui/imgui.h
@@ -1113,7 +1113,7 @@ struct ImDrawList
     IMGUI_API void  AddCircleFilled(const ImVec2& centre, float radius, ImU32 col, int num_segments = 12);
     IMGUI_API void  AddText(const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end = NULL);
     IMGUI_API void  AddText(const ImFont* font, float font_size, const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end = NULL, float wrap_width = 0.0f, const ImVec4* cpu_fine_clip_rect = NULL);
-    IMGUI_API void  AddImage(ImTextureID user_texture_id, const ImVec2& a, const ImVec2& b, const ImVec2& uv0, const ImVec2& uv1, ImU32 col = 0xFFFFFFFF);
+    IMGUI_API void  AddImage(ImTextureID user_texture_id, const ImVec2& a, const ImVec2& b, const ImVec2& uv0 = ImVec2(0,0), const ImVec2& uv1 = ImVec2(1,1), ImU32 col = 0xFFFFFFFF);
     IMGUI_API void  AddPolyline(const ImVec2* points, const int num_points, ImU32 col, bool closed, float thickness, bool anti_aliased);
     IMGUI_API void  AddConvexPolyFilled(const ImVec2* points, const int num_points, ImU32 col, bool anti_aliased);
     IMGUI_API void  AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImVec2& cp1, const ImVec2& pos1, ImU32 col, float thickness, int num_segments = 0);
diff --git a/3rdparty/ocornut-imgui/imgui_draw.cpp b/3rdparty/ocornut-imgui/imgui_draw.cpp
index e91ba3909..09fcf0154 100644
--- a/3rdparty/ocornut-imgui/imgui_draw.cpp
+++ b/3rdparty/ocornut-imgui/imgui_draw.cpp
@@ -291,6 +291,7 @@ void ImDrawList::ChannelsMerge()
 
 void ImDrawList::ChannelsSetCurrent(int idx)
 {
+    IM_ASSERT(idx < _ChannelsCount);
     if (_ChannelsCurrent == idx) return;
     memcpy(&_Channels.Data[_ChannelsCurrent].CmdBuffer, &CmdBuffer, sizeof(CmdBuffer)); // copy 12 bytes, four times
     memcpy(&_Channels.Data[_ChannelsCurrent].IdxBuffer, &IdxBuffer, sizeof(IdxBuffer));