From 95992a255eeadfa8a932d117370148a1f03dfdc8 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Mon, 23 Jan 2023 19:34:48 -0500
Subject: [PATCH] icc: Print every TagData object only once

When several tags refer to the same TagData object, we now only print
it the first time, and print "(see 'foob' above)" the following times,
where `foob` is the tag identifier where we printed it the first time.
---
 Userland/Utilities/icc.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Userland/Utilities/icc.cpp b/Userland/Utilities/icc.cpp
index 2b6b189322..57c338813f 100644
--- a/Userland/Utilities/icc.cpp
+++ b/Userland/Utilities/icc.cpp
@@ -91,9 +91,19 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     outln("");
 
     outln("tags:");
-    profile->for_each_tag([](auto tag_signature, auto tag_data) {
+    HashMap<Gfx::ICC::TagData*, Gfx::ICC::TagSignature> tag_data_to_first_signature;
+    profile->for_each_tag([&tag_data_to_first_signature](auto tag_signature, auto tag_data) {
         outln("{}: {}, offset {}, size {}", tag_signature, tag_data->type(), tag_data->offset(), tag_data->size());
 
+        // Print tag data only the first time it's seen.
+        // (Different sigatures can refer to the same data.)
+        auto it = tag_data_to_first_signature.find(tag_data);
+        if (it != tag_data_to_first_signature.end()) {
+            outln("    (see {} above)", it->value);
+            return;
+        }
+        tag_data_to_first_signature.set(tag_data, tag_signature);
+
         if (tag_data->type() == Gfx::ICC::CurveTagData::Type) {
             auto& curve = static_cast<Gfx::ICC::CurveTagData&>(*tag_data);
             if (curve.values().is_empty()) {