releasetools: Keep the original RangeSet for 'uses_shared_blocks' case.

Setting 'uses_shared_blocks' indicates that the block list for a given
file is incomplete, as some of the blocks are "owned" by others. As a
result, such a file will be skipped from imgdiff'ing.

This CL makes a copy of the original block list before removing the
shared blocks. It uses the original RangeSet as the value of
extra['uses_shared_blocks']. validate_target_files.py will try to read
the file as in the original RangeSet, unless the original list is also
incomplete or has non-monotonic ranges.

Test: Run validate_target_files on a target that uses
      `BOARD_EXT4_SHARE_DUP_BLOCKS := true`.
Change-Id: I259e871ecc249ba0c14b5796bef413185a1b8242
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index fe63458..4c452ad 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -827,10 +827,10 @@
     ranges = image.file_map[entry]
 
     # If a RangeSet has been tagged as using shared blocks while loading the
-    # image, its block list must be already incomplete due to that reason. Don't
-    # give it 'incomplete' tag to avoid messing up the imgdiff stats.
+    # image, check the original block list to determine its completeness. Note
+    # that the 'incomplete' flag would be tagged to the original RangeSet only.
     if ranges.extra.get('uses_shared_blocks'):
-      continue
+      ranges = ranges.extra['uses_shared_blocks']
 
     if RoundUpTo4K(info.file_size) > ranges.size() * 4096:
       ranges.extra['incomplete'] = True
diff --git a/tools/releasetools/sparse_img.py b/tools/releasetools/sparse_img.py
index 5ebb1f0..7919ba4 100644
--- a/tools/releasetools/sparse_img.py
+++ b/tools/releasetools/sparse_img.py
@@ -248,15 +248,21 @@
         ranges = rangelib.RangeSet.parse(ranges)
 
         if allow_shared_blocks:
-          # Find the shared blocks that have been claimed by others.
+          # Find the shared blocks that have been claimed by others. If so, tag
+          # the entry so that we can skip applying imgdiff on this file.
           shared_blocks = ranges.subtract(remaining)
           if shared_blocks:
-            ranges = ranges.subtract(shared_blocks)
-            if not ranges:
+            non_shared = ranges.subtract(shared_blocks)
+            if not non_shared:
               continue
 
-            # Tag the entry so that we can skip applying imgdiff on this file.
-            ranges.extra['uses_shared_blocks'] = True
+            # There shouldn't anything in the extra dict yet.
+            assert not ranges.extra, "Non-empty RangeSet.extra"
+
+            # Put the non-shared RangeSet as the value in the block map, which
+            # has a copy of the original RangeSet.
+            non_shared.extra['uses_shared_blocks'] = ranges
+            ranges = non_shared
 
         out[fn] = ranges
         assert ranges.size() == ranges.intersect(remaining).size()
diff --git a/tools/releasetools/validate_target_files.py b/tools/releasetools/validate_target_files.py
index ae8253d..eeb802b 100755
--- a/tools/releasetools/validate_target_files.py
+++ b/tools/releasetools/validate_target_files.py
@@ -89,13 +89,20 @@
         logging.warning('Skipping %s that has incomplete block list', entry)
         continue
 
+      # Use the original RangeSet if applicable, which includes the shared
+      # blocks. And this needs to happen before checking the monotonicity flag.
+      if ranges.extra.get('uses_shared_blocks'):
+        file_ranges = ranges.extra['uses_shared_blocks']
+      else:
+        file_ranges = ranges
+
       # TODO(b/79951650): Handle files with non-monotonic ranges.
-      if not ranges.monotonic:
+      if not file_ranges.monotonic:
         logging.warning(
-            'Skipping %s that has non-monotonic ranges: %s', entry, ranges)
+            'Skipping %s that has non-monotonic ranges: %s', entry, file_ranges)
         continue
 
-      blocks_sha1 = image.RangeSha1(ranges)
+      blocks_sha1 = image.RangeSha1(file_ranges)
 
       # The filename under unpacked directory, such as SYSTEM/bin/sh.
       unpacked_name = os.path.join(
@@ -104,7 +111,7 @@
       file_sha1 = unpacked_file.sha1
       assert blocks_sha1 == file_sha1, \
           'file: %s, range: %s, blocks_sha1: %s, file_sha1: %s' % (
-              entry, ranges, blocks_sha1, file_sha1)
+              entry, file_ranges, blocks_sha1, file_sha1)
 
   logging.info('Validating file consistency.')
 
@@ -311,9 +318,9 @@
   if info_dict.get("avb_enable") == "true":
     logging.info('Verifying Verified Boot 2.0 (AVB) images...')
 
-    # Temporarily disable the verification for AVB-signed images, due to the
-    # dependency on PyCrypto in `avbtool verify_image` (Bug: 119624011).
-    logging.info('Temporarily disabled due to b/119624011')
+    # TODO(b/120517892): Temporarily disable the verification for AVB-signed
+    # images. Needing supporting changes in caller to pass in the desired keys.
+    logging.info('Temporarily disabled due to b/120517892')
 
 
 def main():