Added unit test for inflate with Z_FINISH and no window.

This test decompresses a small git pack object with the text:
"alone in the dark". By providing inflate with Z_FINISH, it should not use a
sliding window according to zlib docs. We purposefully limit the read buffer
size to trigger CHECK mode to bail early.

test/cmake/test-issues.cmake

@@ -66,3 +66,7 @@ add_test(NAME GH-751
     -DTEST_NAME=GH-751-test-txt
     -DINPUT=${CMAKE_CURRENT_SOURCE_DIR}/GH-751/test.txt
     -P ${CMAKE_CURRENT_SOURCE_DIR}/cmake/compress-and-verify.cmake)
+
+set(TEST_COMMAND ${MINIDEFLATE_COMMAND} 
+    "-d;-k;-s;4;-r;25;${CMAKE_CURRENT_SOURCE_DIR}/GH-1600/packobj.gz")
+add_test(NAME GH-1600 COMMAND ${TEST_COMMAND})

test/minideflate.c

@@ -167,6 +167,12 @@ void inflate_params(FILE *fin, FILE *fout, int32_t read_buf_size, int32_t write_
 
         do {
             err = PREFIX(inflate)(&d_stream, flush);
+
+            /* Ignore Z_BUF_ERROR if we are finishing and read buffer size is 
+             * purposefully limited */
+            if (flush == Z_FINISH && err == Z_BUF_ERROR && read_buf_size != BUFSIZE)
+                err = Z_OK;
+
             if (err == Z_STREAM_END) break;
             CHECK_ERR(err, "inflate");