From b02c184829f4fcaef85cdfda4d33298e25535473 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Mon, 27 Apr 2026 21:08:40 +0200
Subject: [PATCH] Add more error checking, correct caret positioning

---
 Common/Render/Text/draw_text_cocoa.mm | 45 +++++++++++++++++++++++++++
 Common/UI/View.cpp                    |  6 +++-
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/Common/Render/Text/draw_text_cocoa.mm b/Common/Render/Text/draw_text_cocoa.mm
index 91fa6c0d81..a98084112d 100644
--- a/Common/Render/Text/draw_text_cocoa.mm
+++ b/Common/Render/Text/draw_text_cocoa.mm
@@ -237,9 +237,23 @@ bool TextDrawerCocoa::DrawStringBitmap(std::vector<uint8_t> &bitmapData, TextStr
 
 	NSString* string = [[NSString alloc] initWithBytes:str.data() length:str.length() encoding: NSUTF8StringEncoding];
 
+	// If UTF-8 fails, fallback to ASCII to prevent nil
+	if (!string) {
+		string = [[NSString alloc] initWithBytes:str.data() length:str.length() encoding:NSASCIIStringEncoding];
+	}
+	// Skip if string creation failed
+	if (!string) {
+		return false;
+	}
+
 	NSDictionary* attributes = iter->second->attributes;
 	NSAttributedString* as = [[NSAttributedString alloc] initWithString:string attributes:attributes];
 
+	// Safety check for AttributedString allocation
+	if (!as) {
+		return false;
+	}
+
 	// Figure out how big an image we need.
 	// We re-use MeasureString here.
 	float w, h;
@@ -267,6 +281,14 @@ bool TextDrawerCocoa::DrawStringBitmap(std::vector<uint8_t> &bitmapData, TextStr
 	CGBitmapInfo bitmapInfo = kCGImageAlphaPremultipliedLast;
 	CGContextRef ctx = CGBitmapContextCreate(bitmap, bmWidth, bmHeight, 8, bmWidth*4, space, bitmapInfo);
 	CGColorSpaceRelease(space);
+
+	// Safety check for CGContext creation
+	if (!ctx) {
+		WARN_LOG(Log::G3D, "Failed to create CGBitmapContext");
+		delete [] bitmap;
+		return false;
+	}
+
 	// CGContextSetRGBStrokeColor(ctx, 1.0, 1.0, 1.0, 1.0); // white background
 	CGContextSetStrokeColorWithColor(ctx, [ColorType whiteColor].CGColor);
 	CGContextSetFillColorWithColor(ctx, [ColorType whiteColor].CGColor);
@@ -277,8 +299,30 @@ bool TextDrawerCocoa::DrawStringBitmap(std::vector<uint8_t> &bitmapData, TextStr
 	float lineY = 0.0;
 	for (std::string_view line : lines) {
 		NSString *string = [[NSString alloc] initWithBytes:line.data() length:line.size() encoding: NSUTF8StringEncoding];
+
+		// If UTF-8 fails, fallback to ASCII to prevent nil
+		if (!string) {
+			string = [[NSString alloc] initWithBytes:line.data() length:line.size() encoding:NSASCIIStringEncoding];
+		}
+		// Skip empty or failed strings to prevent crash
+		if (!string) {
+			continue;
+		}
+
 		NSAttributedString* as = [[NSAttributedString alloc] initWithString:string attributes:attributes];
+
+		// Safety check for AttributedString allocation
+		if (!as) {
+			continue;
+		}
+
 		CTLineRef ctline = CTLineCreateWithAttributedString((CFAttributedStringRef)as);
+
+		// Core Text safety check
+		if (!ctline) {
+			continue;
+		}
+
 		CGFloat ascent, descent, leading;
 		double fWidth = CTLineGetTypographicBounds(ctline, &ascent, &descent, &leading);
 
@@ -349,6 +393,7 @@ bool TextDrawerCocoa::DrawStringBitmap(std::vector<uint8_t> &bitmapData, TextStr
 		_assert_msg_(false, "Bad TextDrawer format");
 	}
 
+	CGContextRelease(ctx);
 	delete [] bitmap;
 	return true;
 }
diff --git a/Common/UI/View.cpp b/Common/UI/View.cpp
index aa606ddf73..489d03868c 100644
--- a/Common/UI/View.cpp
+++ b/Common/UI/View.cpp
@@ -1298,13 +1298,17 @@ void TextEdit::Draw(UIContext &dc) {
 
 	if (selectAtX_ >= 0) {
 		caret_ = -1;
-		for (int i = 0; i <= text_.size(); i++) {
+		for (int i = 0; i <= text_.size(); ) {
 			dc.MeasureText(dc.GetTheme().uiFont, 1.0f, 1.0f, textToDisplay.substr(0, i), &w, &h, ALIGN_VCENTER | ALIGN_LEFT | align_);
 			float charX = w - scrollPos_;
 			if (charX >= selectAtX_ - 3) {
 				caret_ = i;
 				break;
 			}
+			if (i >= text_.size()) {
+				break;
+			}
+			u8_inc(text_.c_str(), &i);
 		}
 		if (caret_ == -1) {
 			caret_ = (int)text_.size();