From 35701a5e7f00c6984b86b7407a74c474dc547889 Mon Sep 17 00:00:00 2001
From: Sergey Fedorov <barracuda@macos-powerpc.org>
Date: Tue, 21 Jul 2026 14:02:37 +0000
Subject: [PATCH 52/71] =?UTF-8?q?fix(macos):=20decode=20any=20image=20form?=
 =?UTF-8?q?at=20for=20inline=20images=20=E2=80=94=20frontend?=
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Split from the original commit f3aa7ca9b (upstream-history split into
vendor/frontend layers, 2026-07-21): this half covers the frontend-side
image-decode change (TerminalSession.cpp). The accompanying Screen.cpp
change is a vendor-layer edit.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LzTmVgP2ruMz987VJ78k77
---
 src/contour_macos/TerminalSession.cpp | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/contour_macos/TerminalSession.cpp b/src/contour_macos/TerminalSession.cpp
index d990bd8d..c9eb0390 100644
--- a/src/contour_macos/TerminalSession.cpp
+++ b/src/contour_macos/TerminalSession.cpp
@@ -103,8 +103,20 @@ namespace
     [[nodiscard]] std::optional<vtbackend::Image::Data> decodePngViaImageIO(
         vtbackend::ImageFormat format, std::span<uint8_t const> data, vtbackend::ImageSize& size)
     {
-        if (format != vtbackend::ImageFormat::PNG)
-            return std::nullopt;
+        // ImageIO (CGImageSource) sniffs the container from the data itself and decodes PNG, JPEG,
+        // GIF, TIFF, BMP, ... so we do NOT gate on `format`: the engine always passes PNG for this
+        // callback, but an iTerm2 sender may inline a JPEG. Decoding whatever ImageIO recognizes is
+        // both correct and strictly more capable than honoring the (advisory) format hint.
+        (void) format;
+
+        if (data.size() >= 4)
+            std::fprintf(stderr,
+                         "decodeImageIO: %zu bytes, magic %02x %02x %02x %02x\n",
+                         data.size(),
+                         data[0],
+                         data[1],
+                         data[2],
+                         data[3]);
 
         CFDataRef cfData = CFDataCreateWithBytesNoCopy(
             nullptr, data.data(), static_cast<CFIndex>(data.size()), kCFAllocatorNull);
@@ -113,6 +125,10 @@ namespace
 
         CGImageSourceRef source = CGImageSourceCreateWithData(cfData, nullptr);
         CGImageRef image = source ? CGImageSourceCreateImageAtIndex(source, 0, nullptr) : nullptr;
+        std::fprintf(stderr,
+                     "decodeImageIO: source=%p image=%p\n",
+                     (void*) source,
+                     (void*) image);
 
         std::optional<vtbackend::Image::Data> result;
         if (image)