/vsizip/: add read support for Deflate64 (fixes #7013)

autotest/gcore/vsizip.py

@@ -724,3 +724,36 @@ def test_vsizip_byte_zip64_local_header_zeroed():
         "/vsizip/data/byte_zip64_local_header_zeroed.zip/byte.tif"
     ).size
     assert size == 736
+
+
+###############################################################################
+def test_vsizip_deflate64():
+
+    filename = "/vsizip/data/deflate64.zip/100k_lines.txt"
+    size = gdal.VSIStatL(filename).size
+    assert size == 2188890
+
+    f = gdal.VSIFOpenL(filename, "rb")
+    assert f
+    try:
+        data = gdal.VSIFReadL(1, size, f)
+        assert len(data) == size
+        assert len(gdal.VSIFReadL(1, 1, f)) == 0
+        assert gdal.VSIFSeekL(f, 0, 0) == 0
+        data2 = gdal.VSIFReadL(1, size, f)
+        len_data2 = len(data2)
+        assert len_data2 == size
+        assert data2 == data
+        for (pos, nread) in [
+            (10000, 1000),
+            (1, 1),
+            (size - 1, 1),
+            (size // 2, size // 2 + 10),
+        ]:
+            assert gdal.VSIFSeekL(f, pos, 0) == 0
+            data2 = gdal.VSIFReadL(1, nread, f)
+            len_data2 = len(data2)
+            assert len_data2 == min(nread, size - pos), (pos, nread)
+            assert data2 == data[pos : pos + len_data2], (pos, nread)
+    finally:
+        gdal.VSIFCloseL(f)

frmts/zlib/contrib/infback9/CMakeLists.txt

@@ -0,0 +1,18 @@
+add_library(
+  infback9 OBJECT
+  infback9.c
+  inftree9.c
+  minified_zutil.c)
+set_property(TARGET infback9 PROPERTY POSITION_INDEPENDENT_CODE ${GDAL_OBJECT_LIBRARIES_POSITION_INDEPENDENT_CODE})
+target_sources(${GDAL_LIB_TARGET_NAME} PRIVATE $<TARGET_OBJECTS:infback9>)
+target_compile_options(infback9 PRIVATE ${GDAL_C_WARNING_FLAGS})
+if (MSVC)
+  target_compile_options(infback9 PRIVATE ${GDAL_SOFTWARNFLAGS} /wd4131)
+endif ()
+
+include(GdalDriverHelper)
+if (GDAL_USE_ZLIB_INTERNAL)
+  gdal_add_vendored_lib(infback9 libz)
+else()
+  gdal_target_link_libraries(infback9 PRIVATE ZLIB::ZLIB)
+endif ()

frmts/zlib/contrib/infback9/README

@@ -0,0 +1,10 @@
+Modified copy of zlib from https://github.com/brianhelba/zipfile-deflate64
+(at https://github.com/cielavenir/zlib_infback9_resumable/tree/beaec8dc39f5caa86e808611b10f2ea0ab8720c2)
+
+zipfile-deflate64 modified copy has logic to save & restore
+state at beginning and end of inflateBack9(), to allow incremental decoding.
+
+GDAL's changes are regarding the "left" and "put" variables
+
+GDAL also adds a inflateBack9Copy() to allow snapshoting of decompression
+state.