Use English lower casing

In Turkish, I becomes ı instead of i, which is a problem when matching
things like "AllowedIPs".

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -21,6 +21,7 @@ import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 
@@ -117,7 +118,7 @@ public final class WgQuickBackend implements Backend {
             stream.write(config.toWgQuickString().getBytes(StandardCharsets.UTF_8));
         }
         String command = String.format("wg-quick %s '%s'",
-                state.toString().toLowerCase(), tempFile.getAbsolutePath());
+                state.toString().toLowerCase(Locale.ENGLISH), tempFile.getAbsolutePath());
         if (state == State.UP)
             command = "cat /sys/module/wireguard/version && " + command;
         final int result = Application.getRootShell().run(null, command);

app/src/main/java/com/wireguard/android/fragment/TunnelListFragment.java

@@ -53,6 +53,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
@@ -117,8 +118,8 @@ public class TunnelListFragment extends BaseFragment {
                     throw new IllegalArgumentException("Illegal file name: " + name);
                 name = name.substring(idx + 1);
             }
-            boolean isZip = name.toLowerCase().endsWith(".zip");
-            if (name.toLowerCase().endsWith(".conf"))
+            boolean isZip = name.toLowerCase(Locale.ENGLISH).endsWith(".zip");
+            if (name.toLowerCase(Locale.ENGLISH).endsWith(".conf"))
                 name = name.substring(0, name.length() - ".conf".length());
             else if (!isZip)
                 throw new IllegalArgumentException("File must be .conf or .zip");
@@ -137,7 +138,7 @@ public class TunnelListFragment extends BaseFragment {
                                 continue;
                             name = name.substring(name.lastIndexOf('/') + 1);
                         }
-                        if (name.toLowerCase().endsWith(".conf"))
+                        if (name.toLowerCase(Locale.ENGLISH).endsWith(".conf"))
                             name = name.substring(0, name.length() - ".conf".length());
                         else
                             continue;

app/src/main/java/com/wireguard/android/preference/VersionPreference.java

@@ -17,6 +17,8 @@ import com.wireguard.android.Application;
 import com.wireguard.android.BuildConfig;
 import com.wireguard.android.R;
 
+import java.util.Locale;
+
 public class VersionPreference extends Preference {
     @Nullable private String versionSummary;
 
@@ -24,11 +26,11 @@ public class VersionPreference extends Preference {
         super(context, attrs);
 
         Application.getBackendAsync().thenAccept(backend -> {
-            versionSummary = getContext().getString(R.string.version_summary_checking, backend.getTypeName().toLowerCase());
+            versionSummary = getContext().getString(R.string.version_summary_checking, backend.getTypeName().toLowerCase(Locale.ENGLISH));
             Application.getAsyncWorker().supplyAsync(backend::getVersion).whenComplete((version, exception) -> {
                 versionSummary = exception == null
                         ? getContext().getString(R.string.version_summary, backend.getTypeName(), version)
-                        : getContext().getString(R.string.version_summary_unknown, backend.getTypeName().toLowerCase());
+                        : getContext().getString(R.string.version_summary_unknown, backend.getTypeName().toLowerCase(Locale.ENGLISH));
                 notifyChanged();
             });
         });

app/src/main/java/com/wireguard/config/Interface.java

@@ -15,6 +15,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 
@@ -64,7 +65,7 @@ public final class Interface {
         for (final CharSequence line : lines) {
             final Attribute attribute = Attribute.parse(line)
                     .orElseThrow(() -> new ParseException("[Interface]", line, "Syntax error"));
-            switch (attribute.getKey().toLowerCase()) {
+            switch (attribute.getKey().toLowerCase(Locale.ENGLISH)) {
                 case "address":
                     builder.parseAddresses(attribute.getValue());
                     break;

app/src/main/java/com/wireguard/config/Peer.java

@@ -13,6 +13,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 
@@ -54,7 +55,7 @@ public final class Peer {
         for (final CharSequence line : lines) {
             final Attribute attribute = Attribute.parse(line)
                     .orElseThrow(() -> new ParseException("[Peer]", line, "Syntax error"));
-            switch (attribute.getKey().toLowerCase()) {
+            switch (attribute.getKey().toLowerCase(Locale.ENGLISH)) {
                 case "allowedips":
                     builder.parseAllowedIPs(attribute.getValue());
                     break;