meta.ini: revert to upstream CamelCase, canonicalize on read

Restore upstream MO2's exact key cases (gameName, installationFile,
nexusDescription, etc.) in readMeta/saveMeta/doInstall/createMod —
matches mod-shipped meta.ini cases, so on Linux Qt6's case-sensitive
QSettings IniFormat, setValue updates in place without producing a
duplicate key.

normalizeMetaIniCase() repurposed: instead of folding everything to
lowercase (which mismatched the upstream-style setValue calls and
caused the very dupes it was trying to fix), it now canonicalizes
known per-mod meta.ini keys to their upstream CamelCase, deduping
case-insensitive collisions per section. Cleans up dirty files
written during the 5d1fb29 -> 1f19892 window so they collapse to a
single canonical key per setting on first read.

Tests updated to assert canonical-CamelCase output.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

6 files changed, 173 insertions, 134 deletions

diff --git a/src/src/installationmanager.cpp b/src/src/installationmanager.cpp
index 09e2a36..3e58a2a 100644
--- a/src/src/installationmanager.cpp
+++ b/src/src/installationmanager.cpp
@@ -549,8 +549,8 @@ InstallationResult InstallationManager::doInstall(GuessedValue<QString>& modName
 
   // overwrite settings only if they are actually are available or haven't been set
   // before
-  if ((gameName != "") || !settingsFile.contains("gamename")) {
-    settingsFile.setValue("gamename", gameName);
+  if ((gameName != "") || !settingsFile.contains("gameName")) {
+    settingsFile.setValue("gameName", gameName);
   }
   if ((modID != 0) || !settingsFile.contains("modid")) {
     settingsFile.setValue("modid", modID);
@@ -561,15 +561,15 @@ InstallationResult InstallationManager::doInstall(GuessedValue<QString>& modName
                    VersionInfo(settingsFile.value("version").toString()))))) {
     settingsFile.setValue("version", version);
   }
-  if (!newestVersion.isEmpty() || !settingsFile.contains("newestversion")) {
-    settingsFile.setValue("newestversion", newestVersion);
+  if (!newestVersion.isEmpty() || !settingsFile.contains("newestVersion")) {
+    settingsFile.setValue("newestVersion", newestVersion);
   }
   // issue #51 used to overwrite the manually set categories
   if (!settingsFile.contains("category")) {
     settingsFile.setValue("category", QString::number(categoryID));
   }
-  settingsFile.setValue("nexusfilestatus", fileCategoryID);
-  settingsFile.setValue("installationfile", storeMetaPath(m_CurrentFile));
+  settingsFile.setValue("nexusFileStatus", fileCategoryID);
+  settingsFile.setValue("installationFile", storeMetaPath(m_CurrentFile));
   settingsFile.setValue("repository", repository);
 
   if (!merge) {
diff --git a/src/src/metainiutils.cpp b/src/src/metainiutils.cpp
index 7af170f..4ba38b6 100644
--- a/src/src/metainiutils.cpp
+++ b/src/src/metainiutils.cpp
@@ -24,6 +24,54 @@ bool endsInOddBackslashes(const QByteArray& line)
   return (n % 2) == 1;
 }
 
+// Canonical case for keys that appear in per-mod meta.ini, taken from
+// upstream MO2's setValue/value calls in modinforegular.cpp,
+// installationmanager.cpp, and organizercore.cpp.
+const QHash<QByteArray, QByteArray>& canonicalKeyMap()
+{
+  static const QHash<QByteArray, QByteArray> map = {
+      {"author", "author"},
+      {"category", "category"},
+      {"color", "color"},
+      {"comments", "comments"},
+      {"converted", "converted"},
+      {"endorsed", "endorsed"},
+      {"fileid", "fileid"},
+      {"gamename", "gameName"},
+      {"hascustomurl", "hasCustomURL"},
+      {"ignoredversion", "ignoredVersion"},
+      {"installationfile", "installationFile"},
+      {"lastnexusquery", "lastNexusQuery"},
+      {"lastnexusupdate", "lastNexusUpdate"},
+      {"modid", "modid"},
+      {"newestversion", "newestVersion"},
+      {"nexuscategory", "nexusCategory"},
+      {"nexusdescription", "nexusDescription"},
+      {"nexusfilestatus", "nexusFileStatus"},
+      {"nexuslastmodified", "nexusLastModified"},
+      {"notes", "notes"},
+      {"repository", "repository"},
+      {"tracked", "tracked"},
+      {"uploader", "uploader"},
+      {"uploaderurl", "uploaderUrl"},
+      {"url", "url"},
+      {"validated", "validated"},
+      {"version", "version"},
+  };
+  return map;
+}
+
+// Returns the canonical case for `key` if known, otherwise `key` unchanged.
+QByteArray canonicalize(const QByteArray& key)
+{
+  const auto& map = canonicalKeyMap();
+  const auto it   = map.find(key.toLower());
+  if (it != map.end()) {
+    return it.value();
+  }
+  return key;
+}
+
 }  // namespace
 
 bool normalizeMetaIniCase(const QString& path)
@@ -52,7 +100,6 @@ bool normalizeMetaIniCase(const QString& path)
   struct Entry
   {
     bool isKey = false;
-    QByteArray key;          // lowercased
     QByteArray rawLine;      // for non-key lines
     QByteArray fullKeyLine;  // for key lines, possibly multi-line via \\\n
   };
@@ -61,7 +108,7 @@ bool normalizeMetaIniCase(const QString& path)
   {
     QByteArray header;  // [Name] line, empty for the implicit pre-header section
     QList<Entry> entries;
-    QHash<QByteArray, qsizetype> indexByKey;
+    QHash<QByteArray, qsizetype> indexByLowerKey;
   };
 
   QList<Section> sections;
@@ -104,21 +151,21 @@ bool normalizeMetaIniCase(const QString& path)
       full.append(rawLines[i]);
     }
 
-    const int fullEq           = full.indexOf('=');
-    const QByteArray rawKey    = full.left(fullEq).trimmed();
-    const QByteArray valuePart = full.mid(fullEq);  // includes '='
-    const QByteArray lowerKey  = rawKey.toLower();
-    if (rawKey != lowerKey) {
+    const int fullEq             = full.indexOf('=');
+    const QByteArray rawKey      = full.left(fullEq).trimmed();
+    const QByteArray valuePart   = full.mid(fullEq);  // includes '='
+    const QByteArray lowerKey    = rawKey.toLower();
+    const QByteArray canonicalKey = canonicalize(rawKey);
+    if (rawKey != canonicalKey) {
       changed = true;
     }
 
     Entry e;
     e.isKey       = true;
-    e.key         = lowerKey;
-    e.fullKeyLine = lowerKey + valuePart;
+    e.fullKeyLine = canonicalKey + valuePart;
 
-    auto it = cur.indexByKey.find(lowerKey);
-    if (it != cur.indexByKey.end()) {
+    auto it = cur.indexByLowerKey.find(lowerKey);
+    if (it != cur.indexByLowerKey.end()) {
       Entry& prev = cur.entries[it.value()];
       const QByteArray newVal =
           valuePart.size() > 1 ? valuePart.mid(1).trimmed() : QByteArray();
@@ -135,7 +182,7 @@ bool normalizeMetaIniCase(const QString& path)
       changed = true;
     } else {
       cur.entries.push_back(std::move(e));
-      cur.indexByKey.insert(lowerKey, cur.entries.size() - 1);
+      cur.indexByLowerKey.insert(lowerKey, cur.entries.size() - 1);
     }
   }
   sections.push_back(std::move(cur));
diff --git a/src/src/metainiutils.h b/src/src/metainiutils.h
index c043742..0086747 100644
--- a/src/src/metainiutils.h
+++ b/src/src/metainiutils.h
@@ -6,17 +6,19 @@
 namespace MetaIniUtils
 {
 
-// Pre-normalize a Qt INI file so QSettings (case-sensitive in IniFormat on
-// Linux/Qt6) does not produce duplicate-cased keys when `setValue("foo", x)`
-// is invoked on a file already containing `Foo=...`.
+// Canonicalize the keys in a per-mod meta.ini to the case used by upstream
+// MO2's setValue/value calls (e.g. "gameName", "installationFile").
 //
-// Lowercases all keys, deduplicates per-section (keeping the latest
-// non-empty value), and preserves comments, blank lines, and ordering of
-// surviving keys. Multi-line values (trailing `\` continuations) are
-// preserved as a single logical entry.
+// Qt6's QSettings IniFormat is case-sensitive on Linux, so a meta.ini
+// containing both "gameName=" and "gamename=" surfaces as two distinct
+// keys. This helper folds case-insensitively-equal keys to a single entry
+// using the canonical CamelCase, keeping the non-empty value when one is
+// blank, otherwise the later occurrence wins.
 //
-// No-op if the file does not exist or has no case mismatches / duplicates.
-// Returns true if the file was modified.
+// Unknown keys keep their original case and are still deduped.
+//
+// No-op if the file does not exist, is empty, or contains no case
+// mismatches / duplicates. Returns true if the file was modified.
 bool normalizeMetaIniCase(const QString& path);
 
 }  // namespace MetaIniUtils
diff --git a/src/src/modinforegular.cpp b/src/src/modinforegular.cpp
index 3978f2e..c59706d 100644
--- a/src/src/modinforegular.cpp
+++ b/src/src/modinforegular.cpp
@@ -113,21 +113,21 @@ void ModInfoRegular::readMeta()
   QSettings metaFile(metaPath, QSettings::IniFormat);
   m_Comments           = metaFile.value("comments", "").toString();
   m_Notes              = metaFile.value("notes", "").toString();
-  QString const tempGameName = metaFile.value("gamename", m_GameName).toString();
+  QString const tempGameName = metaFile.value("gameName", m_GameName).toString();
   if (tempGameName.size())
     m_GameName = tempGameName;
   m_NexusID = metaFile.value("modid", -1).toInt();
   m_Version.parse(metaFile.value("version", "").toString());
-  m_NewestVersion    = metaFile.value("newestversion", "").toString();
-  m_IgnoredVersion   = metaFile.value("ignoredversion", "").toString();
+  m_NewestVersion    = metaFile.value("newestVersion", "").toString();
+  m_IgnoredVersion   = metaFile.value("ignoredVersion", "").toString();
   m_InstallationFile =
-      loadMetaPath(metaFile.value("installationfile", "").toString());
-  m_NexusDescription = metaFile.value("nexusdescription", "").toString();
-  m_NexusFileStatus  = metaFile.value("nexusfilestatus", "1").toInt();
-  m_NexusCategory    = metaFile.value("nexuscategory", 0).toInt();
+      loadMetaPath(metaFile.value("installationFile", "").toString());
+  m_NexusDescription = metaFile.value("nexusDescription", "").toString();
+  m_NexusFileStatus  = metaFile.value("nexusFileStatus", "1").toInt();
+  m_NexusCategory    = metaFile.value("nexusCategory", 0).toInt();
   m_Author           = metaFile.value("author", "").toString();
   m_Uploader         = metaFile.value("uploader", "").toString();
-  m_UploaderUrl      = metaFile.value("uploaderurl", "").toString();
+  m_UploaderUrl      = metaFile.value("uploaderUrl", "").toString();
   m_Repository       = metaFile.value("repository", "Nexus").toString();
   m_Converted        = metaFile.value("converted", false).toBool();
   m_Validated        = metaFile.value("validated", false).toBool();
@@ -181,8 +181,8 @@ void ModInfoRegular::readMeta()
   // always read the url
   m_CustomURL = metaFile.value("url").toString();
 
-  if (metaFile.contains("hascustomurl")) {
-    m_HasCustomURL = metaFile.value("hascustomurl").toBool();
+  if (metaFile.contains("hasCustomURL")) {
+    m_HasCustomURL = metaFile.value("hasCustomURL").toBool();
   } else {
     if (m_NexusID > 0) {
       // the mod id is valid, disable the custom url
@@ -196,13 +196,13 @@ void ModInfoRegular::readMeta()
   }
 
   m_LastNexusQuery = QDateTime::fromString(
-      metaFile.value("lastnexusquery", "").toString(), Qt::ISODate);
+      metaFile.value("lastNexusQuery", "").toString(), Qt::ISODate);
   m_LastNexusUpdate = QDateTime::fromString(
-      metaFile.value("lastnexusupdate", "").toString(), Qt::ISODate);
+      metaFile.value("lastNexusUpdate", "").toString(), Qt::ISODate);
   m_NexusLastModified = QDateTime::fromString(
-      metaFile.value("nexuslastmodified", QDateTime::currentDateTimeUtc()).toString(),
+      metaFile.value("nexusLastModified", QDateTime::currentDateTimeUtc()).toString(),
       Qt::ISODate);
-  m_NexusCategory = metaFile.value("nexuscategory", 0).toInt();
+  m_NexusCategory = metaFile.value("nexusCategory", 0).toInt();
   m_Color         = metaFile.value("color", QColor()).value<QColor>();
   m_TrackedState  = metaFile.value("tracked", false).toBool()
                         ? TrackedState::TRACKED_TRUE
@@ -285,26 +285,26 @@ void ModInfoRegular::saveMeta()
       temp.erase(m_PrimaryCategory);
       metaFile.setValue("category", QString("%1").arg(m_PrimaryCategory) + "," +
                                         SetJoin(temp, ","));
-      metaFile.setValue("newestversion", m_NewestVersion.canonicalString());
-      metaFile.setValue("ignoredversion", m_IgnoredVersion.canonicalString());
+      metaFile.setValue("newestVersion", m_NewestVersion.canonicalString());
+      metaFile.setValue("ignoredVersion", m_IgnoredVersion.canonicalString());
       metaFile.setValue("version", m_Version.canonicalString());
-      metaFile.setValue("installationfile", storeMetaPath(m_InstallationFile));
+      metaFile.setValue("installationFile", storeMetaPath(m_InstallationFile));
       metaFile.setValue("repository", m_Repository);
-      metaFile.setValue("gamename", m_GameName);
+      metaFile.setValue("gameName", m_GameName);
       metaFile.setValue("modid", m_NexusID);
       metaFile.setValue("comments", m_Comments);
       metaFile.setValue("notes", m_Notes);
-      metaFile.setValue("nexusdescription", m_NexusDescription);
+      metaFile.setValue("nexusDescription", m_NexusDescription);
       metaFile.setValue("url", m_CustomURL);
-      metaFile.setValue("hascustomurl", m_HasCustomURL);
-      metaFile.setValue("nexusfilestatus", m_NexusFileStatus);
-      metaFile.setValue("lastnexusquery", m_LastNexusQuery.toString(Qt::ISODate));
-      metaFile.setValue("lastnexusupdate", m_LastNexusUpdate.toString(Qt::ISODate));
-      metaFile.setValue("nexuslastmodified", m_NexusLastModified.toString(Qt::ISODate));
-      metaFile.setValue("nexuscategory", m_NexusCategory);
+      metaFile.setValue("hasCustomURL", m_HasCustomURL);
+      metaFile.setValue("nexusFileStatus", m_NexusFileStatus);
+      metaFile.setValue("lastNexusQuery", m_LastNexusQuery.toString(Qt::ISODate));
+      metaFile.setValue("lastNexusUpdate", m_LastNexusUpdate.toString(Qt::ISODate));
+      metaFile.setValue("nexusLastModified", m_NexusLastModified.toString(Qt::ISODate));
+      metaFile.setValue("nexusCategory", m_NexusCategory);
       metaFile.setValue("author", m_Author);
       metaFile.setValue("uploader", m_Uploader);
-      metaFile.setValue("uploaderurl", m_UploaderUrl);
+      metaFile.setValue("uploaderUrl", m_UploaderUrl);
       metaFile.setValue("converted", m_Converted);
       metaFile.setValue("validated", m_Validated);
       metaFile.setValue("color", m_Color);
diff --git a/src/src/organizercore.cpp b/src/src/organizercore.cpp
index bc28969..8b3171e 100644
--- a/src/src/organizercore.cpp
+++ b/src/src/organizercore.cpp
@@ -964,9 +964,9 @@ MOBase::IModInterface* OrganizerCore::createMod(GuessedValue<QString>& name)
   if (!result.merged()) {
     settingsFile.setValue("modid", 0);
     settingsFile.setValue("version", "");
-    settingsFile.setValue("newestversion", "");
+    settingsFile.setValue("newestVersion", "");
     settingsFile.setValue("category", 0);
-    settingsFile.setValue("installationfile", "");
+    settingsFile.setValue("installationFile", "");
 
     settingsFile.remove("installedFiles");
     settingsFile.beginWriteArray("installedFiles", 0);
diff --git a/src/tests/test_metainiutils.cpp b/src/tests/test_metainiutils.cpp
index aef5998..faec068 100644
--- a/src/tests/test_metainiutils.cpp
+++ b/src/tests/test_metainiutils.cpp
@@ -40,96 +40,99 @@ TEST(MetaIniUtils, NoOpOnMissingFile)
   EXPECT_FALSE(MetaIniUtils::normalizeMetaIniCase(path));
 }
 
-// Sanity: file with only lowercase keys is left untouched.
-TEST(MetaIniUtils, NoOpOnAlreadyLowercase)
+// Sanity: file with only canonical-case keys is left untouched.
+TEST(MetaIniUtils, NoOpOnAlreadyCanonical)
 {
   QTemporaryDir dir;
   ASSERT_TRUE(dir.isValid());
   const auto* contents = "[General]\n"
                          "author=Aether\n"
-                         "category=\"11,\"\n";
+                         "category=\"11,\"\n"
+                         "gameName=Skyrim\n"
+                         "installationFile=Foo.7z\n";
   const QString path = writeIni(dir, contents);
   EXPECT_FALSE(MetaIniUtils::normalizeMetaIniCase(path));
   EXPECT_EQ(QByteArray(contents), readAll(path));
 }
 
-// The reported bug: pre-existing CamelCase keys + lowercase setValue() leaves
-// duplicates on Linux/Qt6. Normalize must fold case-only duplicates.
-TEST(MetaIniUtils, DedupesCaseOnlyDuplicates)
+// The reported bug: pre-existing CamelCase keys + a lowercased duplicate
+// (left over from the 5d1fb29 era) coexist on Linux/Qt6. Normalize must fold
+// them back to the upstream MO2 case.
+TEST(MetaIniUtils, FoldsLowercaseDuplicatesToUpstreamCase)
 {
   QTemporaryDir dir;
   ASSERT_TRUE(dir.isValid());
-  // Mirrors what ModInfoRegular::saveMeta() leaves behind when meta.ini
-  // already had CamelCase keys: both casings coexist, and the lowercase
-  // copy may even be empty because readMeta() couldn't see the original.
+  // Mirrors the dirty meta.ini in the bug report: CamelCase keys with
+  // empty/default values from the broken saveMeta(), and lowercase keys
+  // carrying the real preserved values.
   const auto* contents =
       "[General]\n"
-      "Author=Aether\n"
-      "Category=11\n"
-      "Color=@Variant(\\0\\0\\0\\x43\\x1\\xff\\xff\\x43\\x43\\xff\\xff\\xff\\xff\\0\\0)\n"
-      "Comments=keep me\n"
-      "Converted=false\n"
-      "author=\n"
-      "category=\"11,\"\n"
-      "comments=\n"
-      "converted=true\n";
+      "gameName=SkyrimSE\n"
+      "gamename=Skyrim\n"
+      "installationFile=\n"
+      "installationfile=Sweet Mother HD-4947-2-0.7z\n"
+      "newestVersion=\n"
+      "newestversion=2.0.0.0\n"
+      "lastNexusQuery=2026-05-01T17:28:22Z\n"
+      "lastnexusquery=2026-05-01T17:27:42Z\n";
   const QString path = writeIni(dir, contents);
   EXPECT_TRUE(MetaIniUtils::normalizeMetaIniCase(path));
 
-  // Open via QSettings and verify exactly one canonical lowercase key per
-  // logical setting.
+  // Open via QSettings using the upstream CamelCase keys.
   QSettings s(path, QSettings::IniFormat);
-  EXPECT_EQ(QStringList({"author", "category", "color", "comments", "converted"}),
-            s.allKeys());
+  // Each logical setting collapses to a single canonical-case key.
+  QStringList keys = s.allKeys();
+  std::sort(keys.begin(), keys.end());
+  EXPECT_EQ(QStringList({"gameName", "installationFile", "lastNexusQuery",
+                         "newestVersion"}),
+            keys);
 
-  // Empty lowercase duplicate should NOT clobber the non-empty CamelCase
-  // value — `Comments=keep me` survives over `comments=`.
-  EXPECT_EQ("Aether", s.value("author").toString());
-  EXPECT_EQ("keep me", s.value("comments").toString());
+  // Empty CamelCase line dropped in favor of the non-empty lowercase value.
+  EXPECT_EQ("Sweet Mother HD-4947-2-0.7z",
+            s.value("installationFile").toString());
+  EXPECT_EQ("2.0.0.0", s.value("newestVersion").toString());
 
-  // For non-empty duplicates the latest write wins, mirroring last-writer
-  // semantics so QSettings doesn't reintroduce stale data.
-  EXPECT_EQ("11,", s.value("category").toString());
-  EXPECT_TRUE(s.value("converted").toBool());
+  // Both halves were non-empty for gameName and lastNexusQuery — last writer
+  // wins, mirroring saveMeta()'s order-of-writes.
+  EXPECT_EQ("Skyrim", s.value("gameName").toString());
+  EXPECT_EQ("2026-05-01T17:27:42Z", s.value("lastNexusQuery").toString());
 
-  // Color value (containing escaped binary) round-trips intact.
   const QByteArray after = readAll(path);
-  EXPECT_TRUE(after.contains(
-      "color=@Variant(\\0\\0\\0\\x43\\x1\\xff\\xff\\x43\\x43\\xff\\xff\\xff\\xff\\0\\0)"))
-      << after.toStdString();
-  EXPECT_FALSE(after.contains("Author="));
-  EXPECT_FALSE(after.contains("Color="));
+  EXPECT_FALSE(after.contains("gamename="));
+  EXPECT_FALSE(after.contains("installationfile="));
+  EXPECT_FALSE(after.contains("newestversion="));
+  EXPECT_FALSE(after.contains("lastnexusquery="));
 }
 
 // QSettings IniFormat supports multi-line values via trailing-`\` line
-// continuation. Continuation lines must travel with their key when the key is
-// renamed to lowercase, otherwise the value gets corrupted.
+// continuation. Continuation lines must travel with their key when the key
+// is canonicalized, otherwise the value gets corrupted.
 TEST(MetaIniUtils, PreservesLineContinuations)
 {
   QTemporaryDir dir;
   ASSERT_TRUE(dir.isValid());
   const auto* contents = "[General]\n"
-                         "NotesField=line one\\\n"
+                         "nexusdescription=line one\\\n"
                          "  continued line two\n"
-                         "Author=Aether\n";
+                         "author=Aether\n";
   const QString path = writeIni(dir, contents);
   EXPECT_TRUE(MetaIniUtils::normalizeMetaIniCase(path));
 
   const QByteArray after = readAll(path);
-  EXPECT_TRUE(after.contains("notesfield=line one\\\n"));
+  EXPECT_TRUE(after.contains("nexusDescription=line one\\\n"));
   EXPECT_TRUE(after.contains("  continued line two"));
-  EXPECT_FALSE(after.contains("NotesField="));
+  EXPECT_FALSE(after.contains("nexusdescription="));
 }
 
 // Plugin settings live in nested `[Plugins\<name>]` sections. The dedupe
-// logic must scope per-section — `Foo=` under [General] must not collide
-// with `foo=` under [Plugins\Whatever].
+// logic must scope per-section — a key under [General] must not collide
+// with the same lowercase key under [Plugins\Whatever].
 TEST(MetaIniUtils, DedupesPerSection)
 {
   QTemporaryDir dir;
   ASSERT_TRUE(dir.isValid());
   const auto* contents = "[General]\n"
-                         "Foo=top\n"
+                         "gameName=Skyrim\n"
                          "[Plugins\\Sample]\n"
                          "Foo=plugin\n"
                          "foo=plugin-dup\n";
@@ -137,54 +140,41 @@ TEST(MetaIniUtils, DedupesPerSection)
   EXPECT_TRUE(MetaIniUtils::normalizeMetaIniCase(path));
 
   QSettings s(path, QSettings::IniFormat);
-  EXPECT_EQ("top", s.value("foo").toString());
+  EXPECT_EQ("Skyrim", s.value("gameName").toString());
   s.beginGroup("Plugins/Sample");
-  EXPECT_EQ("plugin-dup", s.value("foo").toString());
+  // Unknown plugin key keeps its first-seen case, last-writer wins on value.
+  EXPECT_EQ("plugin-dup", s.value("Foo").toString());
   s.endGroup();
 }
 
-// End-to-end: reproduce the exact symptom from the bug report — install
-// path opens QSettings, writes lowercase keys; without normalization the
-// resulting file ends up with CamelCase + lowercase duplicates.
-TEST(MetaIniUtils, FixesQSettingsDuplicationOnLinux)
+// End-to-end: an upstream-style saveMeta sequence over a normalized file
+// updates in place — no second case-mismatched key appears.
+TEST(MetaIniUtils, UpstreamSaveMetaProducesNoDupes)
 {
   QTemporaryDir dir;
   ASSERT_TRUE(dir.isValid());
-  // Pre-existing meta.ini in CamelCase (e.g. shipped inside the mod
-  // archive, or migrated from MO2 Windows).
+  // Dirty file from the 5d1fb29 era — CamelCase + lowercase coexist.
   const auto* preexisting = "[General]\n"
-                            "Author=Aether\n"
-                            "Category=11\n"
-                            "Comments=keep me\n";
+                            "gameName=SkyrimSE\n"
+                            "gamename=Skyrim\n"
+                            "installationFile=\n"
+                            "installationfile=Foo.7z\n";
   const QString path = writeIni(dir, preexisting);
 
-  // Without normalization, lowercase setValue adds NEW keys alongside the
-  // CamelCase ones — confirm the bug exists in the bare QSettings flow.
-  {
-    QSettings s(path, QSettings::IniFormat);
-    s.setValue("author", "Aether");
-    s.setValue("category", "11,");
-    s.setValue("comments", "");
-  }
-  const QByteArray dirty = readAll(path);
-  EXPECT_TRUE(dirty.contains("Author=Aether"));
-  EXPECT_TRUE(dirty.contains("author=Aether"));
-
-  // Normalize and re-run the same install-style writes. After this the
-  // file must have exactly one casing per key.
+  // Normalize folds lowercase dupes back into the upstream CamelCase keys.
   EXPECT_TRUE(MetaIniUtils::normalizeMetaIniCase(path));
+
+  // Upstream-style saveMeta: CamelCase setValue on every key.
   {
     QSettings s(path, QSettings::IniFormat);
-    s.setValue("author", "Aether");
-    s.setValue("category", "11,");
+    s.setValue("gameName", s.value("gameName"));
+    s.setValue("installationFile", s.value("installationFile"));
   }
 
   const QByteArray clean = readAll(path);
-  EXPECT_FALSE(clean.contains("Author="));
-  EXPECT_FALSE(clean.contains("Category="));
-  EXPECT_FALSE(clean.contains("Comments="));
-  EXPECT_TRUE(clean.contains("author=Aether"));
-  EXPECT_TRUE(clean.contains("category=\"11,\""));
-  // The non-empty original Comments value survived the empty duplicate.
-  EXPECT_TRUE(clean.contains("comments=keep me"));
+  EXPECT_TRUE(clean.contains("gameName=Skyrim"));
+  EXPECT_TRUE(clean.contains("installationFile=Foo.7z"));
+  // No lowercase dupes resurrected.
+  EXPECT_FALSE(clean.contains("gamename="));
+  EXPECT_FALSE(clean.contains("installationfile="));
 }