Add test for out-of-order writes

References #1220.  References #1277.

test/integration-test-main.sh

@@ -670,7 +670,13 @@ function test_open_second_fd {
 
 function test_write_multiple_offsets {
     describe "test writing to multiple offsets"
-    ../../write_multiple_offsets.py ${TEST_TEXT_FILE}
+    ../../write_multiple_offsets.py ${TEST_TEXT_FILE} 1024 1 $((16 * 1024 * 1024)) 1 $((18 * 1024 * 1024)) 1
+    rm_test_file ${TEST_TEXT_FILE}
+}
+
+function test_write_multiple_offsets_backwards {
+    describe "test writing to multiple offsets"
+    ../../write_multiple_offsets.py ${TEST_TEXT_FILE} $((20 * 1024 * 1024 + 1)) 1 $((10 * 1024 * 1024)) 1
     rm_test_file ${TEST_TEXT_FILE}
 }
 
@@ -780,6 +786,7 @@ function add_all_tests {
     add_tests test_concurrent_writes
     add_tests test_open_second_fd
     add_tests test_write_multiple_offsets
+    add_tests test_write_multiple_offsets_backwards
     add_tests test_content_type
     add_tests test_truncate_cache
 }

test/write_multiple_offsets.py

@@ -3,16 +3,15 @@
 import os
 import sys
 
+if len(sys.argv) < 4 or len(sys.argv) % 2 != 0:
+    sys.exit("Usage: %s OUTFILE OFFSET_1 SIZE_1 [OFFSET_N SIZE_N]...")
+
 filename = sys.argv[1]
-data = bytes('a', 'utf-8')
 
 fd = os.open(filename, os.O_CREAT | os.O_TRUNC | os.O_WRONLY)
 try:
-    os.pwrite(fd, data, 1024)
-    os.pwrite(fd, data, 16 * 1024 * 1024)
-    os.pwrite(fd, data, 18 * 1024 * 1024)
+    for i in range(2, len(sys.argv), 2):
+        data = bytes("a" * int(sys.argv[i+1]), 'utf-8')
+        os.pwrite(fd, data, int(sys.argv[i]))
 finally:
     os.close(fd)
-
-stat = os.lstat(filename)
-assert stat.st_size == 18 * 1024 * 1024 + 1