[tinker] Do not reset versionToRemove field so that old patch can be removed after new patch is applied.

Author: tangyinsheng

tinker-android/tinker-android-lib/src/main/java/com/tencent/tinker/lib/listener/DefaultPatchListener.java

@@ -134,13 +134,6 @@ protected int patchCheck(String path, String patchMd5) {
                 && loadResult != null && loadResult.useInterpretMode;
 
         if (!repairOptNeeded) {
-            if (manager.isTinkerLoaded() && loadResult != null) {
-                String currentVersion = loadResult.currentVersion;
-                if (patchMd5.equals(currentVersion)) {
-                    return ShareConstants.ERROR_PATCH_ALREADY_APPLY;
-                }
-            }
-
             // Hit if we have already applied patch but main process did not restart.
             final String patchDirectory = manager.getPatchDirectory().getAbsolutePath();
             File patchInfoLockFile = SharePatchFileUtil.getPatchInfoLockFile(patchDirectory);

tinker-android/tinker-android-lib/src/main/java/com/tencent/tinker/lib/patch/DexDiffPatchInternal.java

@@ -198,7 +198,8 @@ private static boolean patchDexExtractViaDexDiff(Context context, String patchVe
     }
 
     private static boolean checkClassNDexFiles(final String dexFilePath) {
-       if (patchList.isEmpty() || !isVmArt) {
+        classNDexInfo.clear();
+        if (patchList.isEmpty() || !isVmArt) {
             return false;
         }
         ShareDexDiffPatchInfo testInfo = null;

tinker-android/tinker-android-lib/src/main/java/com/tencent/tinker/lib/patch/UpgradePatch.java

@@ -123,7 +123,20 @@ public boolean tryPatch(Context context, String tempPatchPath, PatchResult patch
             }
             // if it is interpret now, use changing flag to wait main process
             final String finalOatDir = usingInterpret ? ShareConstants.CHANING_DEX_OPTIMIZE_PATH : oldInfo.oatDir;
-            newInfo = new SharePatchInfo(oldInfo.oldVersion, patchMd5, isProtectedApp, "", Build.FINGERPRINT, finalOatDir, false);
+            if (!patchMd5.equals(oldInfo.newVersion) && !oldInfo.newVersion.equals(oldInfo.oldVersion)) {
+                // Currently applied patch is not the same as last applied one and the last applied one is not loaded,
+                // so we can delete the last applied patch to avoid patch artifacts accumulating.
+                final String patchName = SharePatchFileUtil.getPatchVersionDirectory(oldInfo.newVersion);
+                SharePatchFileUtil.deleteDir(new File(patchDirectory, patchName));
+            }
+            final String versionToRemove;
+            if (patchMd5.equals(oldInfo.versionToRemove)) {
+                // If we re-applied a patch that marks to be removed, clear the marker.
+                versionToRemove = "";
+            } else {
+                versionToRemove = oldInfo.versionToRemove;
+            }
+            newInfo = new SharePatchInfo(oldInfo.oldVersion, patchMd5, isProtectedApp, versionToRemove, Build.FINGERPRINT, finalOatDir, false);
         } else {
             newInfo = new SharePatchInfo("", patchMd5, isProtectedApp, "", Build.FINGERPRINT, ShareConstants.DEFAULT_DEX_OPTIMIZE_PATH, false);
         }

tinker-android/tinker-android-loader/src/main/java/com/tencent/tinker/loader/TinkerLoader.java

@@ -172,6 +172,9 @@ private void tryLoadPatchFilesInternal(TinkerApplication app, Intent resultInten
                         ShareTinkerInternals.killProcessExceptMain(app);
                         SharePatchFileUtil.deleteDir(patchVersionDirFullPath);
                     }
+                } else {
+                    patchInfo.versionToRemove = "";
+                    SharePatchInfo.rewritePatchInfoFileWithLock(patchInfoFile, patchInfo, patchInfoLockFile);
                 }
             }
             if (patchInfo.isRemoveInterpretOATDir) {