K2GO-510 fix(clone): name the shared APK after the ABIs it carries

CLAUDE.md

@@ -235,6 +235,9 @@ validation, allowing config-directive/URL injection.
   parse boundary (returns `null` -> existing "invalid QR" toast), and
   `RsyncManager` re-checks defensively before writing the daemon config / building
   the client URL. Reusable by the remaining injection fixes (S4, D2) as they migrate.
+- `data/ApkAbiReader` (K2GO-510): lists the `lib/<abi>/` folders of the APK that
+  Clone "Send app" shares; `domain/ApkShareName.archLabel` names the file after them.
+  **Legacy seam:** `CloneFragment.sharedApkName()`.
 
 **Slice (DONE) — deploy module-name allowlist (`org.iiab.controller.deploy.domain`)**
 Phase-1 security slice closing tech-debt **D2** (command injection). The install

controller/app/src/main/java/org/appdevforall/k2go/redesign/CloneFragment.java

@@ -33,12 +33,14 @@
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
 import java.io.File;
+import java.io.IOException;
 import org.appdevforall.k2go.ApkServer;
 import org.appdevforall.k2go.BuildConfig;
 import org.appdevforall.k2go.R;
 import org.appdevforall.k2go.ServerController;
 import org.appdevforall.k2go.SyncHandshakeHelper;
 import org.appdevforall.k2go.env.EnvironmentLock;
+import org.appdevforall.k2go.sync.data.ApkAbiReader;
 import org.appdevforall.k2go.sync.domain.ApkShareName;
 import org.appdevforall.k2go.hotspot.HotspotPermissions;
 import org.appdevforall.k2go.hotspot.LocalHotspotManager;
@@ -886,8 +888,7 @@ private void startApkServer() {
         if (apkServer != null) return;
         try {
             String apkPath = requireContext().getApplicationInfo().sourceDir;
-            String arch = (archBits() == 64) ? "arm64-v8a" : "armeabi-v7a";
-            apkFileName = ApkShareName.fileName(BuildConfig.VERSION_NAME, arch);
+            apkFileName = sharedApkName(apkPath);
             apkServer = new ApkServer(shareConfig.apkPort, apkPath, apkFileName);
             apkServer.start();
         } catch (Exception e) {
@@ -896,6 +897,19 @@ private void startApkServer() {
         }
     }
 
+    /** K2GO-510: name the shared APK after the ABIs it carries (ADFA-4540), not after this phone. */
+    private String sharedApkName(String apkPath) {
+        String arch;
+        try {
+            arch = ApkShareName.archLabel(ApkAbiReader.abis(apkPath));
+        } catch (IOException | RuntimeException e) {
+            // The name is a hint: it must never block the share.
+            Log.w("IIAB-Clone", "Could not read the APK ABIs", e);
+            arch = null;   // "unknown": do not guess
+        }
+        return ApkShareName.fileName(BuildConfig.VERSION_NAME, arch);
+    }
+
     private void stopApkServer() {
         if (apkServer != null) {
             try { apkServer.stop(); } catch (Exception ignored) { }
@@ -907,7 +921,9 @@ private void stopApkServer() {
     private void shareApkViaSheet() {
         try {
             File apk = new File(requireContext().getApplicationInfo().sourceDir);
-            Uri uri = FileProvider.getUriForFile(requireContext(), requireContext().getPackageName() + ".provider", apk);
+            // Without a display name the receiver gets the file as "base.apk".
+            Uri uri = FileProvider.getUriForFile(requireContext(), requireContext().getPackageName() + ".provider",
+                    apk, apkFileName != null ? apkFileName : sharedApkName(apk.getPath()));
             Intent i = new Intent(Intent.ACTION_SEND)
                     .setType("application/vnd.android.package-archive")
                     .putExtra(Intent.EXTRA_STREAM, uri)

controller/app/src/main/java/org/appdevforall/k2go/sync/data/ApkAbiReader.java

@@ -0,0 +1,43 @@
+/*
+ * ============================================================================
+ * Name        : ApkAbiReader.java
+ * Author      : AppDevForAll
+ * Copyright   : Copyright (c) 2026 AppDevForAll
+ * Description : Reads the native ABIs that an APK carries (its lib/<abi>/
+ *               folders), so the shared file is named after what it contains,
+ *               not after the phone that sends it (ADFA-4540, K2GO-510).
+ *               JDK zip only, so it is testable on a plain JVM.
+ * ============================================================================
+ */
+package org.appdevforall.k2go.sync.data;
+
+import java.io.IOException;
+import java.util.Enumeration;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+
+public final class ApkAbiReader {
+
+    private ApkAbiReader() {
+    }
+
+    /** Distinct ABI folder names under {@code lib/} in the APK; empty when it has no native libs. */
+    public static Set<String> abis(String apkPath) throws IOException {
+        Set<String> abis = new LinkedHashSet<>();
+        try (ZipFile zip = new ZipFile(apkPath)) {
+            Enumeration<? extends ZipEntry> entries = zip.entries();
+            while (entries.hasMoreElements()) {
+                ZipEntry entry = entries.nextElement();
+                String name = entry.getName();
+                int slash = name.indexOf('/', 4);
+                // A bare lib/<abi>/ directory entry carries no library.
+                if (!entry.isDirectory() && name.startsWith("lib/") && slash > 4) {
+                    abis.add(name.substring(4, slash));
+                }
+            }
+        }
+        return abis;
+    }
+}

controller/app/src/main/java/org/appdevforall/k2go/sync/domain/ApkShareName.java

@@ -4,12 +4,12 @@
  * Author      : AppDevForAll
  * Copyright   : Copyright (c) 2026 AppDevForAll
  * Description : Domain rule: the coloquial file name the shared APK travels
- *               under when a peer downloads it over the Share tab. Stamps the
+ *               under (Clone "Send app": QR download and share sheet). Stamps the
  *               brand, the build version and the arch so the receiver can tell
  *               exactly which build they were handed offline, instead of the old
  *               "-Latest" (true but ambiguous). Pure, no android.*; the single
- *               source of truth for the download name so the HTTP header and the
- *               QR URL cannot drift apart. ADFA-4540.
+ *               source of truth for the download name so the HTTP header, the
+ *               QR URL and the share sheet cannot drift apart. ADFA-4540.
  * ============================================================================
  */
 package org.appdevforall.k2go.sync.domain;

controller/app/src/test/java/org/appdevforall/k2go/sync/data/ApkAbiReaderTest.java

@@ -0,0 +1,67 @@
+package org.appdevforall.k2go.sync.data;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+/** The ABIs come from the APK's lib/<abi>/ folders only. Pure JVM. */
+public class ApkAbiReaderTest {
+
+    @Rule
+    public TemporaryFolder tmp = new TemporaryFolder();
+
+    private String apk(String... entries) throws IOException {
+        File f = tmp.newFile();
+        try (ZipOutputStream zip = new ZipOutputStream(new FileOutputStream(f))) {
+            for (String e : entries) {
+                zip.putNextEntry(new ZipEntry(e));
+                zip.closeEntry();
+            }
+        }
+        return f.getPath();
+    }
+
+    @Test
+    public void universalApkListsEveryAbiOnce() throws IOException {
+        String path = apk("classes.dex",
+                "lib/arm64-v8a/libproot.so", "lib/arm64-v8a/libtermux.so",
+                "lib/armeabi-v7a/libproot.so", "lib/x86/libproot.so", "lib/x86_64/libproot.so");
+        assertEquals(new LinkedHashSet<>(Arrays.asList("arm64-v8a", "armeabi-v7a", "x86", "x86_64")),
+                ApkAbiReader.abis(path));
+    }
+
+    @Test
+    public void singleAbiSplit() throws IOException {
+        assertEquals(Collections.singleton("arm64-v8a"),
+                ApkAbiReader.abis(apk("AndroidManifest.xml", "lib/arm64-v8a/libproot.so")));
+    }
+
+    @Test
+    public void baseWithoutNativeLibsIsEmpty() throws IOException {
+        // A Play config-split base.apk: native libs live in another split.
+        assertEquals(Collections.emptySet(),
+                ApkAbiReader.abis(apk("AndroidManifest.xml", "classes.dex", "assets/lib/x.so", "lib/")));
+    }
+
+    @Test
+    public void emptyAbiDirectoryDoesNotCount() throws IOException {
+        assertEquals(Collections.singleton("arm64-v8a"),
+                ApkAbiReader.abis(apk("lib/x86/", "lib/arm64-v8a/", "lib/arm64-v8a/libproot.so")));
+    }
+
+    @Test(expected = IOException.class)
+    public void unreadableFileThrows() throws IOException {
+        ApkAbiReader.abis(new File(tmp.getRoot(), "missing.apk").getPath());
+    }
+}