Revert^2 "libandroidfw hardening for IncFs"

55ef6167a2c235bd88c7216238b2001b46795b79

Change-Id: I02d4890d181655dfd0a14c188468db512559d27b
Merged-In: I02d4890d181655dfd0a14c188468db512559d27b

1 files changed, 23 insertions, 0 deletions

diff --git a/libs/androidfw/ZipFileRO.cpp b/libs/androidfw/ZipFileRO.cpp
index e77ac3df474c..52e7a70521a1 100644
--- a/libs/androidfw/ZipFileRO.cpp
+++ b/libs/androidfw/ZipFileRO.cpp
@@ -233,6 +233,29 @@ FileMap* ZipFileRO::createEntryFileMap(ZipEntryRO entry) const
 }
 
 /*
+ * Create a new incfs::IncFsFileMap object that spans the data in "entry".
+ */
+std::optional<incfs::IncFsFileMap> ZipFileRO::createEntryIncFsFileMap(ZipEntryRO entry) const
+{
+    const _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
+    const ZipEntry& ze = zipEntry->entry;
+    int fd = GetFileDescriptor(mHandle);
+    size_t actualLen = 0;
+
+    if (ze.method == kCompressStored) {
+        actualLen = ze.uncompressed_length;
+    } else {
+        actualLen = ze.compressed_length;
+    }
+
+    incfs::IncFsFileMap newMap;
+    if (!newMap.Create(fd, ze.offset, actualLen, mFileName)) {
+        return std::nullopt;
+    }
+    return std::move(newMap);
+}
+
+/*
  * Uncompress an entry, in its entirety, into the provided output buffer.
  *
  * This doesn't verify the data's CRC, which might be useful for