Some tests require compat=1.1 and thus set IMGOPTS='compat=1.1'
globally.  That is not how it should be done; instead, they should
simply set _unsupported_imgopts to compat=0.10 (compat=1.1 is the
default anyway).
This makes the tests heed user-specified $IMGOPTS.  Some do not work
with all image options, though, so we need to disable them accordingly.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsky@redhat.com>
Message-id: 
20191107163708.833192-7-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
 _supported_proto file
-
 # Only qcow2v3 and later supports feature bits
-IMGOPTS="compat=1.1"
+_unsupported_imgopts 'compat=0.10'
 
 echo
 echo === Image with unknown incompatible feature bit ===
 
 _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
+# These tests only work for compat=1.1 images with refcount_bits=16
+_unsupported_imgopts 'compat=0.10' 'refcount_bits=\([^1]\|.\([^6]\|$\)\)'
 
 # The repair process will create a large file - so check for availability first
 _require_large_file 64G
 l2_offset=262144 # 0x40000 (XXX: just an assumption)
 l2_offset_after_snapshot=524288 # 0x80000 (XXX: just an assumption)
 
-IMGOPTS="compat=1.1"
-
 OPEN_RW="open -o overlap-check=all $TEST_IMG"
 # Overlap checks are done before write operations only, therefore opening an
 # image read-only makes the overlap-check option irrelevant
 
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
 _supported_proto generic
+# We need zero clusters and snapshots
+_unsupported_imgopts 'compat=0.10' 'refcount_bits=1[^0-9]'
 
-IMGOPTS="compat=1.1"
 IMG_SIZE=64M
 
 echo
 
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
 _supported_proto generic
+# We need zero clusters and snapshots
+_unsupported_imgopts 'compat=0.10' 'refcount_bits=1[^0-9]'
 
 # Intentionally create an unaligned image
-IMGOPTS="compat=1.1"
 IMG_SIZE=$((64 * 1024 * 1024 + 512))
 
 echo
 
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
 _supported_proto generic
+# Internal snapshots are (currently) impossible with refcount_bits=1
+_unsupported_imgopts 'compat=0.10' 'refcount_bits=1[^0-9]'
 
-IMGOPTS="compat=1.1"
 IMG_SIZE=128K
 
 case "$QEMU_DEFAULT_MACHINE" in
 
 
 _supported_fmt qcow2
 _supported_proto file
-
-IMGOPTS="compat=1.1"
+# The code path we want to test here only works for compat=1.1 images
+_unsupported_imgopts 'compat=0.10'
 
 for event in l1_update empty_image_prepare reftable_update refblock_alloc; do