From b610aa1c0cc02c54f4252756d25dcfa4c399fae9 Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Wed, 15 Oct 2025 17:33:33 +0800
Subject: [PATCH] Encode UTF8 non breakingspace (194, 160) as &nbsp; - same as
 chrome

---
 src/browser/dump.zig       | 15 ++++++++++++---
 src/tests/dom/element.html | 13 +++++++++++++
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/browser/dump.zig b/src/browser/dump.zig
index dab2d14d..ccbffed0 100644
--- a/src/browser/dump.zig
+++ b/src/browser/dump.zig
@@ -236,10 +236,10 @@ fn isVoid(elem: *parser.Element) !bool {
     };
 }
 
-fn writeEscapedTextNode(writer: anytype, value: []const u8) !void {
+fn writeEscapedTextNode(writer: *std.Io.Writer, value: []const u8) !void {
     var v = value;
     while (v.len > 0) {
-        const index = std.mem.indexOfAnyPos(u8, v, 0, &.{ '&', '<', '>' }) orelse {
+        const index = std.mem.indexOfAnyPos(u8, v, 0, &.{ '&', '<', '>', 194 }) orelse {
             return writer.writeAll(v);
         };
         try writer.writeAll(v[0..index]);
@@ -247,13 +247,22 @@ fn writeEscapedTextNode(writer: anytype, value: []const u8) !void {
             '&' => try writer.writeAll("&amp;"),
             '<' => try writer.writeAll("&lt;"),
             '>' => try writer.writeAll("&gt;"),
+            194 => {
+                // non breaking space
+                if (v.len > index + 1 and v[index + 1] == 160) {
+                    try writer.writeAll("&nbsp;");
+                    v = v[index + 2 ..];
+                    continue;
+                }
+                try writer.writeByte(194);
+            },
             else => unreachable,
         }
         v = v[index + 1 ..];
     }
 }
 
-fn writeEscapedAttributeValue(writer: anytype, value: []const u8) !void {
+fn writeEscapedAttributeValue(writer: *std.Io.Writer, value: []const u8) !void {
     var v = value;
     while (v.len > 0) {
         const index = std.mem.indexOfAnyPos(u8, v, 0, &.{ '&', '<', '>', '"' }) orelse {
diff --git a/src/tests/dom/element.html b/src/tests/dom/element.html
index 4364ee87..d5794fa2 100644
--- a/src/tests/dom/element.html
+++ b/src/tests/dom/element.html
@@ -326,3 +326,16 @@
   testing.expectEqual("after begin", newElement.innerText);
   testing.expectEqual("afterbegin", newElement.className);
 </script>
+
+<script id=nonBreakingSpace>
+  // Test non-breaking space encoding (critical for React hydration)
+  const div = document.createElement('div');
+  div.innerHTML = 'hello\xa0world';
+  testing.expectEqual('hello\xa0world', div.textContent);
+  testing.expectEqual('hello&nbsp;world', div.innerHTML);
+
+  // Test that outerHTML also encodes non-breaking spaces correctly
+  const p = document.createElement('p');
+  p.textContent = 'XAnge\xa0Privacy';
+  testing.expectEqual('<p>XAnge&nbsp;Privacy</p>', p.outerHTML);
+</script>