From c05470515f8b20a1fa31ffacf0c44debb24b8f29 Mon Sep 17 00:00:00 2001
From: nikneym <halildrk@gmail.com>
Date: Tue, 16 Sep 2025 10:40:38 +0300
Subject: [PATCH] double quotes must be first and last argument of slice if
 provided

---
 src/browser/mime.zig | 84 +++++---------------------------------------
 1 file changed, 9 insertions(+), 75 deletions(-)

diff --git a/src/browser/mime.zig b/src/browser/mime.zig
index babf7072..f1860b1f 100644
--- a/src/browser/mime.zig
+++ b/src/browser/mime.zig
@@ -69,83 +69,17 @@ pub const Mime = struct {
         // https://datatracker.ietf.org/doc/rfc2978/
         if (value.len > 40) return error.CharsetTooBig;
 
-        // If the first char is not a quote, value can be used directly.
-        // Whitespace is not allowed.
-        if (value[0] != '"') {
-            return value;
+        // If the first char is a quote, look for a pair.
+        if (value[0] == '"') {
+            if (value.len < 3 or value[value.len - 1] != '"') {
+                return error.Invalid;
+            }
+
+            return value[1 .. value.len - 1];
         }
 
-        // Search for second quote begins.
-        // Skip the first character.
-        var offset: usize = 1;
-
-        // Charset values are not so large; 128-bit registers should be
-        // more than enough.
-        const vec_size = 16;
-        const Vec = @Vector(vec_size, u8);
-        const UInt = std.meta.Int(.unsigned, vec_size);
-        const block_size = @sizeOf(u64);
-
-        const charset = blk: {
-            // Vector search.
-            while (value.len - offset >= vec_size) : (offset += vec_size) {
-                // Fill a vector with quotes.
-                const quotes: Vec = @splat('"');
-                const chunk: Vec = value[offset..][0..vec_size].*;
-
-                // Check if chunk has double quote byte.
-                const match = @intFromBool(chunk == quotes);
-                // Create an integer out of match and count how much to skip.
-                const skip_by = @ctz(@as(UInt, @bitCast(match)));
-
-                // Found a match.
-                if (skip_by != vec_size) {
-                    break :blk value[1 .. offset + skip_by];
-                }
-            }
-
-            // SWAR search.
-            while (value.len - offset >= block_size) : (offset += block_size) {
-                // Magic number for integer filled with double quote.
-                // [8]u8{ '"', '"', '"', '"', '"', '"', '"', '"' }.
-                const quotes: u64 = 0x2222222222222222;
-                // Load the next chunk as unsigned 64-bit integer.
-                const chunk: u64 = @bitCast(value[offset..][0..block_size].*);
-
-                // XOR with the pattern - bytes equal to quote become 0.
-                const xor_result = chunk ^ quotes;
-
-                const magic: u64 = 0x8080808080808080; // High bit mask for each byte.
-                const sub_result = xor_result -% 0x0101010101010101; // Subtract 1 from each byte.
-                const and_result = sub_result & (~xor_result); // AND with inverted original.
-                const zero_mask = and_result & magic; // Extract high bits (indicates zero bytes).
-
-                // Found a match.
-                if (zero_mask != 0) {
-                    // * Count trailing zeroes.
-                    // * Dividing by byte size (>> 3) converts the bit position to byte index.
-                    const skip_by = @ctz(zero_mask) >> 3;
-                    break :blk value[1 .. offset + skip_by];
-                }
-            }
-
-            // Fallback to scalar search.
-            for (value[offset..], 0..) |c, i| {
-                if (c == '"') {
-                    break :blk value[1 .. offset + i];
-                }
-            }
-
-            // No quote pairs, something is wrong.
-            return error.Invalid;
-        };
-
-        // Make sure we don't end up w/ empty buffer.
-        if (charset.len == 0) {
-            return error.Invalid;
-        }
-
-        return charset;
+        // No quotes.
+        return value;
     }
 
     pub fn parse(input: []u8) !Mime {