Support devices with more than two ABIs on >=21

Also, start using String[] like Android's SUPPORTED_ABIS instead of
Set<String>. Said list of ABIs will always be very short, at most containing a
handful of elements.

F-Droid/src/org/fdroid/fdroid/CompatibilityChecker.java

@@ -18,7 +18,7 @@ public class CompatibilityChecker extends Compatibility {
 
     private Context context;
     private Set<String> features;
-    private Set<String> cpuAbis;
+    private String[] cpuAbis;
     private String cpuAbisDesc;
     private boolean ignoreTouchscreen;
 
@@ -59,8 +59,8 @@ public class CompatibilityChecker extends Compatibility {
 
     private boolean compatibleApi(Utils.CommaSeparatedList nativecode) {
         if (nativecode == null) return true;
-        for (String abi : nativecode) {
+        for (final String abi : nativecode) {
-            if (cpuAbis.contains(abi)) {
+            if (Utils.arrayContains(cpuAbis, abi)) {
                 return true;
             }
         }
@@ -79,7 +79,7 @@ public class CompatibilityChecker extends Compatibility {
         }
 
         if (apk.features != null) {
-            for (String feat : apk.features) {
+            for (final String feat : apk.features) {
                 if (ignoreTouchscreen
                         && feat.equals("android.hardware.touchscreen")) {
                     // Don't check it!

F-Droid/src/org/fdroid/fdroid/Utils.java

@@ -507,4 +507,13 @@ public final class Utils {
         }
     }
 
+    public static <T> boolean arrayContains(final T[] array, final T v) {
+        for (final T e : array) {
+            if (e == v || v != null && v.equals(e)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
 }

F-Droid/src/org/fdroid/fdroid/compat/SupportedArchitectures.java

@@ -1,30 +1,35 @@
 package org.fdroid.fdroid.compat;
 
-import java.util.Set;
-import java.util.HashSet;
-
 import android.annotation.TargetApi;
 import android.os.Build;
 
 public class SupportedArchitectures extends Compatibility {
 
-    private static Set<String> getOneAbi() {
+    private static String[] getAbisDonut() {
-        Set<String> abis = new HashSet<String>(1);
+        return new String[]{Build.CPU_ABI};
-        abis.add(Build.CPU_ABI);
-        return abis;
     }
 
     @TargetApi(8)
-    private static Set<String> getTwoAbis() {
+    private static String[] getAbisFroyo() {
-        Set<String> abis = new HashSet<String>(2);
+        return new String[]{Build.CPU_ABI, Build.CPU_ABI2};
-        abis.add(Build.CPU_ABI);
-        abis.add(Build.CPU_ABI2);
-        return abis;
     }
 
-    public static Set<String> getAbis() {
+    @TargetApi(21)
-        if (hasApi(8)) return getTwoAbis();
+    private static String[] getAbisLollipop() {
-        return getOneAbi();
+        return Build.SUPPORTED_ABIS;
+    }
+
+    /**
+     * The most preferred ABI is the first element in the list.
+     */
+    public static String[] getAbis() {
+        if (hasApi(21)) {
+            return getAbisLollipop();
+        }
+        if (hasApi(8)) {
+            return getAbisFroyo();
+        }
+        return getAbisDonut();
     }
 
 }