From deef227ba2e23d2f68ca21c04c1e838c2341070a Mon Sep 17 00:00:00 2001
From: ocornut <omar@miracleworld.net>
Date: Mon, 18 Aug 2025 14:27:15 +0200
Subject: [PATCH] CalcWordWrapPosition() breaks on \n instead of relying on
 caller to do it + expose ImTextCalcWordWrapNextLineStart().

Should be functional no-op, fingers crossed. Breaking on \n allows caller to count lines reliably.
---
 imgui_draw.cpp    | 15 +++++----------
 imgui_internal.h  |  1 +
 imgui_widgets.cpp |  5 +----
 3 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index c3e4e5a35..a7c9f26db 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -5346,7 +5346,7 @@ ImFontBaked* ImFontAtlasBakedGetOrAdd(ImFontAtlas* atlas, ImFont* font, float fo
 }
 
 // Trim trailing space and find beginning of next line
-static inline const char* CalcWordWrapNextLineStartA(const char* text, const char* text_end)
+const char* ImTextCalcWordWrapNextLineStart(const char* text, const char* text_end)
 {
     while (text < text_end && ImCharIsBlankA(*text))
         text++;
@@ -5398,12 +5398,7 @@ const char* ImFont::CalcWordWrapPosition(float size, const char* text, const cha
         if (c < 32)
         {
             if (c == '\n')
-            {
-                line_width = word_width = blank_width = 0.0f;
-                inside_word = true;
-                s = next_s;
-                continue;
-            }
+                return s; // Direct return, skip "Wrap_width is too small to fit anything" path.
             if (c == '\r')
             {
                 s = next_s;
@@ -5495,7 +5490,7 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
                 text_size.y += line_height;
                 line_width = 0.0f;
                 word_wrap_eol = NULL;
-                s = CalcWordWrapNextLineStartA(s, text_end); // Wrapping skips upcoming blanks
+                s = ImTextCalcWordWrapNextLineStart(s, text_end); // Wrapping skips upcoming blanks
                 continue;
             }
         }
@@ -5619,7 +5614,7 @@ begin:
                 // If the specs for CalcWordWrapPosition() were reworked to optionally return on \n we could combine both.
                 // However it is still better than nothing performing the fast-forward!
                 s = CalcWordWrapPosition(size, s, line_end ? line_end : text_end, wrap_width);
-                s = CalcWordWrapNextLineStartA(s, text_end);
+                s = ImTextCalcWordWrapNextLineStart(s, text_end);
             }
             else
             {
@@ -5673,7 +5668,7 @@ begin:
                 if (y > clip_rect.w)
                     break; // break out of main loop
                 word_wrap_eol = NULL;
-                s = CalcWordWrapNextLineStartA(s, text_end); // Wrapping skips upcoming blanks
+                s = ImTextCalcWordWrapNextLineStart(s, text_end); // Wrapping skips upcoming blanks
                 continue;
             }
         }
diff --git a/imgui_internal.h b/imgui_internal.h
index d0686a9b7..a35631d0d 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -439,6 +439,7 @@ IMGUI_API int           ImTextCountUtf8BytesFromChar(const char* in_text, const
 IMGUI_API int           ImTextCountUtf8BytesFromStr(const ImWchar* in_text, const ImWchar* in_text_end);                        // return number of bytes to express string in UTF-8
 IMGUI_API const char*   ImTextFindPreviousUtf8Codepoint(const char* in_text_start, const char* in_text_curr);                   // return previous UTF-8 code-point.
 IMGUI_API int           ImTextCountLines(const char* in_text, const char* in_text_end);                                         // return number of lines taken by text. trailing carriage return doesn't count as an extra line.
+IMGUI_API const char*   ImTextCalcWordWrapNextLineStart(const char* text, const char* text_end);                                // trim trailing space and find beginning of next line
 
 // Helpers: File System
 #ifdef IMGUI_DISABLE_FILE_FUNCTIONS
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index 8aabd05f5..1adaa2311 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -3917,9 +3917,6 @@ bool ImGui::InputDouble(const char* label, double* v, double step, double step_f
 // - InputText()
 // - InputTextWithHint()
 // - InputTextMultiline()
-// - InputTextGetCharInfo() [Internal]
-// - InputTextReindexLines() [Internal]
-// - InputTextReindexLinesRange() [Internal]
 // - InputTextEx() [Internal]
 // - DebugNodeInputTextState() [Internal]
 //-------------------------------------------------------------------------
@@ -4531,7 +4528,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     IM_ASSERT(buf != NULL && buf_size >= 0);
     IM_ASSERT(!((flags & ImGuiInputTextFlags_CallbackHistory) && (flags & ImGuiInputTextFlags_Multiline)));        // Can't use both together (they both use up/down keys)
     IM_ASSERT(!((flags & ImGuiInputTextFlags_CallbackCompletion) && (flags & ImGuiInputTextFlags_AllowTabInput))); // Can't use both together (they both use tab key)
-    IM_ASSERT(!((flags & ImGuiInputTextFlags_ElideLeft) && (flags & ImGuiInputTextFlags_Multiline)));               // Multiline will not work with left-trimming
+    IM_ASSERT(!((flags & ImGuiInputTextFlags_ElideLeft) && (flags & ImGuiInputTextFlags_Multiline)));              // Multiline does not not work with left-trimming
 
     ImGuiContext& g = *GImGui;
     ImGuiIO& io = g.IO;