tweak: filter redundant flags in flag attrs

brut.apktool/apktool-lib/src/main/java/brut/androlib/res/data/value/ResAttr.java

@@ -135,34 +135,34 @@ protected void serializeBody(XmlSerializer serializer, ResResource res)
     }
 
     protected String getTypeAsString() {
-        String s = "";
+        StringBuilder sb = new StringBuilder();
         if ((mType & TYPE_REFERENCE) != 0) {
-            s += "|reference";
+            sb.append("|reference");
         }
         if ((mType & TYPE_STRING) != 0) {
-            s += "|string";
+            sb.append("|string");
         }
         if ((mType & TYPE_INT) != 0) {
-            s += "|integer";
+            sb.append("|integer");
         }
         if ((mType & TYPE_BOOL) != 0) {
-            s += "|boolean";
+            sb.append("|boolean");
         }
         if ((mType & TYPE_COLOR) != 0) {
-            s += "|color";
+            sb.append("|color");
         }
         if ((mType & TYPE_FLOAT) != 0) {
-            s += "|float";
+            sb.append("|float");
         }
         if ((mType & TYPE_DIMEN) != 0) {
-            s += "|dimension";
+            sb.append("|dimension");
         }
         if ((mType & TYPE_FRACTION) != 0) {
-            s += "|fraction";
+            sb.append("|fraction");
         }
-        if (s.isEmpty()) {
+        if (sb.length() == 0) {
             return null;
         }
-        return s.substring(1);
+        return sb.substring(1);
     }
 }

brut.apktool/apktool-lib/src/main/java/brut/androlib/res/data/value/ResFlagsAttr.java

@@ -55,28 +55,70 @@ public String convertToResXmlFormat(ResScalarValue value) throws AndrolibExcepti
             return super.convertToResXmlFormat(value);
         }
         loadFlags();
-        int intVal = ((ResIntValue) value).getValue();
 
+        int intVal = ((ResIntValue) value).getValue();
         if (intVal == 0) {
             return renderFlags(mZeroFlags);
         }
 
-        FlagItem[] flagItems = new FlagItem[mFlags.length];
-        int[] flags = new int[mFlags.length];
+        FlagItem[] flags = new FlagItem[mFlags.length];
         int flagsCount = 0;
-        for (FlagItem flagItem : mFlags) {
-            int flag = flagItem.flag;
+        int flagsInt = 0;
+
+        for (FlagItem item : mFlags) {
+            int flag = item.flag;
 
-            if ((intVal & flag) != flag) {
+            if ((intVal & flag) != flag || (flagsInt & flag) == flag) {
                 continue;
             }
 
-            if (!isSubpartOf(flag, flags)) {
-                flags[flagsCount] = flag;
-                flagItems[flagsCount++] = flagItem;
+            flags[flagsCount++] = item;
+            flagsInt |= flag;
+
+            if (intVal == flagsInt) {
+                break;
             }
         }
-        return renderFlags(Arrays.copyOf(flagItems, flagsCount));
+
+        if (flagsCount == 0) {
+            throw new AndrolibException(String.format("invalid flags in value: 0x%08x", intVal));
+        }
+
+        // Filter out redundant flags
+        if (flagsCount > 2) {
+            FlagItem[] filtered = new FlagItem[flagsCount];
+            int filteredCount = 0;
+
+            for (int i = 0; i < flagsCount; i++) {
+                FlagItem item = flags[i];
+                int mask = 0;
+
+                // Combine the other flags
+                for (int j = 0; j < flagsCount; j++) {
+                    FlagItem other = flags[j];
+
+                    if (j != i && other != null) {
+                        mask |= other.flag;
+                    }
+                }
+
+                // Keep only if it adds at least one unique bit
+                if ((item.flag & ~mask) != 0) {
+                    filtered[filteredCount++] = item;
+                } else {
+                    flags[i] = null;
+                }
+            }
+
+            flags = filtered;
+            flagsCount = filteredCount;
+        }
+
+        if (flagsCount != flags.length) {
+            flags = Arrays.copyOf(flags, flagsCount);
+        }
+
+        return renderFlags(flags);
     }
 
     @Override
@@ -98,15 +140,6 @@ protected void serializeBody(XmlSerializer serializer, ResResource res)
         }
     }
 
-    private boolean isSubpartOf(int flag, int[] flags) {
-        for (int f : flags) {
-            if ((f & flag) == flag) {
-                return true;
-            }
-        }
-        return false;
-    }
-
     private String renderFlags(FlagItem[] flags) throws AndrolibException {
         StringBuilder sb = new StringBuilder();
         for (FlagItem flag : flags) {
@@ -139,6 +172,8 @@ private void loadFlags() {
         mZeroFlags = Arrays.copyOf(zeroFlags, zeroFlagsCount);
         mFlags = Arrays.copyOf(flags, flagsCount);
 
-        Arrays.sort(mFlags, Comparator.comparingInt((FlagItem item) -> Integer.bitCount(item.flag)).reversed());
+        Arrays.sort(mFlags,
+            Comparator.comparingInt((FlagItem item) -> Integer.bitCount(item.flag)).reversed()
+            .thenComparingInt((FlagItem item) -> item.flag));
     }
 }

brut.apktool/apktool-lib/src/test/java/brut/androlib/aapt2/NetworkConfigTest.java

@@ -65,12 +65,12 @@ public void netSecConfGeneric() throws BrutException {
         Document doc = loadDocument(new File(sTestNewDir, "res/xml/network_security_config.xml"));
 
         // Check if 'system' certificate exists
-        String systemCertExpr = "//base-config//certificates[@src='system']";
+        String systemCertExpr = "/network-security-config/base-config/trust-anchors/certificates[@src='system']";
         NodeList systemCertNodes = evaluateXPath(doc, systemCertExpr, NodeList.class);
         assertTrue(systemCertNodes.getLength() > 0);
 
         // Check if 'user' certificate exists
-        String userCertExpr = "//base-config//certificates[@src='user']";
+        String userCertExpr = "/network-security-config/base-config/trust-anchors/certificates[@src='user']";
         NodeList userCertNodes = evaluateXPath(doc, userCertExpr, NodeList.class);
         assertTrue(userCertNodes.getLength() > 0);
     }