Search for expected keywords in the output of cbfstool tests and not a...

Search for expected keywords in the output of cbfstool tests and not a specific output. (Closes: !42)

Stop trying to track every small change in the output of the "cbfstool print"
command, just search for some expected keywords instead.

- Around 2015 the legacy master header stopped being generated by default:
   https://www.coreboot.org/CBFS#FMAP
   https://review.coreboot.org/c/coreboot/+/10135



- In v4.7, cbfstool added the Comp(ression) column.

- v4.8 or v4.9 added a new header " FMAP REGION: COREBOOT", see new
  contextual diff below.

Signed-off-by: Chris Lamb <lamby@debian.org>

tests/comparators/test_cbfs.py

@@ -19,6 +19,7 @@
 
 import struct
 import pytest
+import re
 import subprocess
 
 from diffoscope.comparators.cbfs import CbfsFile
@@ -122,15 +123,14 @@ def differences(rom1, rom2):
 
 @skip_unless_tools_exist('cbfstool')
 def test_listing(differences):
-    # Newer versions of cbfstool do not create the "legacy" header by default
-    # and thus is missing from the diff.
-    # Even newer versions added a "compression" column.
-
-    assert differences[0].unified_diff in (
-        get_data('cbfs_listing_expected_diff'),
-        get_data('cbfs_listing_no_legacy_header_expected_diff'),
-        get_data('cbfs_listing_comp_column_expected.diff'),  # cbfs >= 4.6
-    )
+    # Compares outputs of: "cbfstool $tmpdir/coreboot*.rom print"
+    #
+    # As the output of this command keeps changing slightly (see
+    # https://salsa.debian.org/reproducible-builds/diffoscope/merge_requests/38/
+    # and the git log of this file), perform only these basic sanity checks.
+
+    assert differences[0].source1.startswith("cbfstool")
+    assert re.search(r'\+text\s.*\sraw\s', differences[0].unified_diff)
 
 
 @skip_unless_tools_exist('cbfstool')

tests/data/cbfs_listing_comp_column_expected.diff

-@@ -1,3 +1,3 @@
- Name                           Offset     Type           Size   Comp
--text                           0x0        raw               446 none
--(empty)                        0x200      null            32152 none
-+text                           0x0        raw               671 none
-+(empty)                        0x300      null            31896 none

tests/data/cbfs_listing_expected_diff

-@@ -1,6 +1,3 @@
--32 kB, bootblocksize 0, romsize 32768, offset 0x0
--alignment: 64 bytes, architecture: x86
--
- Name                           Offset     Type         Size
--text                           0x0        raw          446
--(empty)                        0x200      null         32152
-+text                           0x0        raw          671
-+(empty)                        0x300      null         31896

tests/data/cbfs_listing_no_legacy_header_expected_diff

-@@ -1,3 +1,3 @@
- Name                           Offset     Type         Size
--text                           0x0        raw          446
--(empty)                        0x200      null         32152
-+text                           0x0        raw          671
-+(empty)                        0x300      null         31896