ngtcp2: Fix example server build on 32-bit targets

The example server keeps the file size in a uint64_t and uses it as the
size of a std::span, which clang rejects as narrowing on targets with a
32-bit size_t, such as riscv32:

  examples/server.cc:236:54: error: non-constant-expression cannot be
  narrowed from type 'uint64_t' (aka 'unsigned long long') to
  'size_type' (aka 'unsigned int') in initializer list [-Wc++11-narrowing]

Add a patch that stores the length as a size_t and rejects files too
large to map instead of truncating their size.

AI-Generated: Uses Claude Code
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-networking/recipes-protocols/ngtcp2/ngtcp2/0001-examples-server-Do-not-truncate-file-sizes-on-32-bit.patch

@@ -0,0 +1,63 @@
+From: Khem Raj <khem.raj@oss.qualcomm.com>
+Date: Wed, 21 Oct 2026 09:00:00 -0700
+Subject: [PATCH] examples/server: Do not truncate file sizes on 32-bit
+ targets
+
+FileEntry::len is a uint64_t, but it is used for mmap() and as the size
+of the resp_data std::span, both of which take a size_t. On targets
+where size_t is 32 bits, such as riscv32, clang rejects the narrowing in
+the span initializer:
+
+  examples/server.cc:236:54: error: non-constant-expression cannot be
+  narrowed from type 'uint64_t' (aka 'unsigned long long') to
+  'size_type' (aka 'unsigned int') in initializer list [-Wc++11-narrowing]
+
+The value is already truncated earlier, where st_size is cast to size_t
+before mmap(), so a file larger than the address space would be served
+with the wrong length.
+
+Store the length as a size_t, and fail open_file() with
+Error::INTEGER_OVERFLOW when the file is too large to map, instead of
+truncating its size.
+
+Upstream-Status: Submitted [https://github.com/ngtcp2/ngtcp2/pull/2330]
+Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>
+---
+ examples/server.cc | 7 +++++++
+ examples/server.h  | 2 +-
+ 2 files changed, 8 insertions(+), 1 deletion(-)
+
+--- a/examples/server.cc
++++ b/examples/server.cc
+@@ -31,6 +31,8 @@
+ #include <memory>
+ #include <fstream>
+ #include <iomanip>
++#include <limits>
++#include <utility>
+ 
+ #include <unistd.h>
+ #include <getopt.h>
+@@ -216,6 +218,11 @@
+     close(fd);
+   } else {
+     fe.fd = fd;
++    // A file larger than the address space cannot be mapped.
++    if (std::cmp_greater(st.st_size, std::numeric_limits<size_t>::max())) {
++      close(fd);
++      return std::unexpected{Error::INTEGER_OVERFLOW};
++    }
+     fe.len = static_cast<size_t>(st.st_size);
+     if (fe.len) {
+       fe.map = mmap(nullptr, fe.len, PROT_READ, MAP_SHARED, fd, 0);
+--- a/examples/server.h
++++ b/examples/server.h
+@@ -68,7 +68,7 @@
+ };
+ 
+ struct FileEntry {
+-  uint64_t len{};
++  size_t len{};
+   void *map{};
+   int fd{};
+   uint8_t flags{};

meta-networking/recipes-protocols/ngtcp2/ngtcp2_1.25.0.bb

@@ -4,7 +4,9 @@ BUGTRACKER = "https://github.com/ngtcp2/ngtcp2/issues"
 LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://COPYING;md5=de0966c8ff4f62661a3da92967a75434"
 
-SRC_URI = "gitsm://github.com/ngtcp2/ngtcp2;protocol=https;branch=main;tag=v${PV}"
+SRC_URI = "gitsm://github.com/ngtcp2/ngtcp2;protocol=https;branch=main;tag=v${PV} \
+           file://0001-examples-server-Do-not-truncate-file-sizes-on-32-bit.patch \
+           "
 SRCREV = "f9e9ff01ad2c8116bc09de4f644b0028a61486a6"
 
 DEPENDS = "brotli libev nghttp3"