From 7462ee927557601368d68a3dc31b4f85bbffae0c Mon Sep 17 00:00:00 2001
From: Rom <rom@4kbyte.org>
Date: Sat, 9 May 2026 20:11:32 -0700
Subject: [PATCH] Omit prerelease versions from update selection.

---
 src/AppInstallerCLITests/CompositeSource.cpp  | 40 +++++++++++++++++++
 .../PackageVersionSelection.cpp               | 24 +++++++++++
 2 files changed, 64 insertions(+)

diff --git a/src/AppInstallerCLITests/CompositeSource.cpp b/src/AppInstallerCLITests/CompositeSource.cpp
index b45993ac1a..b6a84a9a33 100644
--- a/src/AppInstallerCLITests/CompositeSource.cpp
+++ b/src/AppInstallerCLITests/CompositeSource.cpp
@@ -761,6 +761,46 @@ TEST_CASE("CompositePackage_AvailableVersions_NoChannelFilteredOut", "[Composite
     REQUIRE(latestVersion->GetProperty(PackageVersionProperty::Channel).get() == channel);
 }
 
+TEST_CASE("CompositePackage_PrereleaseAvailable_StableInstalled_NoUpdate", "[CompositeSource]")
+{
+    // microsoft/winget-pkgs#368913: a higher-precedence pre-release must not be
+    // offered as an upgrade to a stable installation.
+    auto availableVersion = GENERATE("3.14.5"sv, "3.14.5rc1"sv);
+    const bool isPrerelease = (availableVersion == "3.14.5rc1"sv);
+
+    CompositeTestSetup setup;
+    setup.Installed->Everything.Matches.emplace_back(setup.MakeInstalled().WithVersion("3.14.4"sv), Criteria());
+    setup.Available->SearchFunction = [&](const SearchRequest&)
+    {
+        auto manifest = MakeDefaultManifest(availableVersion);
+        // ManifestComparator::GetPreferredInstaller drops Architecture::Unknown on the host.
+        manifest.Installers[0].BaseInstallerType = Manifest::InstallerTypeEnum::Exe;
+        manifest.Installers[0].Arch = Utility::Architecture::Neutral;
+
+        SearchResult result;
+        result.Matches.emplace_back(
+            TestCompositePackage::Make(std::vector<Manifest::Manifest>{ manifest }, setup.Available),
+            Criteria());
+        return result;
+    };
+
+    SearchResult result = setup.Search();
+    REQUIRE(result.Matches.size() == 1);
+
+    auto latest = GetLatestApplicableVersion(result.Matches[0].Package);
+    if (isPrerelease)
+    {
+        REQUIRE_FALSE(latest.UpdateAvailable);
+        REQUIRE_FALSE(latest.LatestApplicableVersion);
+    }
+    else
+    {
+        REQUIRE(latest.UpdateAvailable);
+        REQUIRE(latest.LatestApplicableVersion);
+        REQUIRE(latest.LatestApplicableVersion->GetProperty(PackageVersionProperty::Version).get() == availableVersion);
+    }
+}
+
 TEST_CASE("CompositeSource_MultipleAvailableSources_MatchAll", "[CompositeSource]")
 {
     TestCommon::TestUserSettings testSettings;
diff --git a/src/AppInstallerRepositoryCore/PackageVersionSelection.cpp b/src/AppInstallerRepositoryCore/PackageVersionSelection.cpp
index 5303b6e248..a4422264ca 100644
--- a/src/AppInstallerRepositoryCore/PackageVersionSelection.cpp
+++ b/src/AppInstallerRepositoryCore/PackageVersionSelection.cpp
@@ -10,6 +10,20 @@ namespace AppInstaller::Repository
 {
     namespace
     {
+        // Heuristic: any non-numeric tail in any Part. Catches both 1.0.0-rc.1 (SemVer)
+        // and 1.0.0rc1 (e.g. Python PEP 440); the manifest schema has no IsPrerelease field.
+        bool LooksLikePrerelease(const Utility::Version& version)
+        {
+            for (const auto& part : version.GetParts())
+            {
+                if (!part.Other.empty())
+                {
+                    return true;
+                }
+            }
+            return false;
+        }
+
         std::shared_ptr<IPackage> GetAvailablePackageFromSource(const std::vector<std::shared_ptr<IPackage>>& packages, const std::string_view sourceIdentifier)
         {
             for (const std::shared_ptr<IPackage>& package : packages)
@@ -175,6 +189,9 @@ namespace AppInstaller::Repository
         }
         AppInstaller::Manifest::ManifestComparator manifestComparator{ options };
 
+        const bool installedIsPrerelease = installedVersion &&
+            LooksLikePrerelease(Utility::Version{ installedVersion->GetProperty(PackageVersionProperty::Version) });
+
         auto availableVersionKeys = availableVersions->GetVersionKeys();
         for (const auto& availableVersionKey : availableVersionKeys)
         {
@@ -186,6 +203,13 @@ namespace AppInstaller::Repository
                 continue;
             }
 
+            if (installedVersion && !installedIsPrerelease &&
+                LooksLikePrerelease(Utility::Version{ availableVersion->GetProperty(PackageVersionProperty::Version) }))
+            {
+                // Stable installations are not auto-upgraded to a pre-release
+                continue;
+            }
+
             if (evaluator.EvaluatePinType(availableVersion) != AppInstaller::Pinning::PinType::Unknown)
             {
                 // Pinned