This directory contains the LZMA SDK code used in building the self-extracting
Windows installer.

The src/ directory contains an almost-unmodified copy of the 7-zip source code
version 18.05, as downloaded from https://www.7-zip.org/a/lzma1805.7z (linked
from https://www.7-zip.org/sdk.html) on August 30, 2018. As stated in
DOC/lzma-sdk.txt and on the web page, this code is in the public domain. A few
modifications have been made to this copy of the source code. Those
modifications are contained in mozilla_customizations.diff, which should be
found in the same directory as this file.

The firefox/ directory contains 7zSD.sfx, a 32-bit Windows executable built
from the Visual C++ 6 project found in the src/CPP/7zip/Bundles/SFXSetup/
directory. The "ReleaseD" configuration was used. Including a compiled binary
in the source tree is certainly not preferred, but is necessary in this case
because the code does not build cleanly under more recent compilers. Using an
older toolchain also allows us to keep this executable running on older Windows
versions which are no longer supported by the build system used for the main
application; that means we can show an error message specifically informing
users that their OS is too old, instead of the generic "not a valid Win32
application" error that Windows would generate if we used the newer toolchain
and that isn't very helpful to most users.

The firefox/ directory also contains an icon and a manifest which were edited
into 7zSD.sfx's resources after build time. The icon had to be added this way
as opposed to just replacing the included 7-zip icon because the resource
compiler included with VC6 does not support the 128x128 PNG image included in
our icon file. Similarly, the manifest had to be edited in because the older
resource compiler does not support manifests (and the 7-zip build files do not
try to use any).