tests: disable revlog compression in test-generaldelta.t (issue6867)

The revlog compression makes a lot of numbers unstable. Since checking revlog
compression is not the goal of this test, we disable the compression to get
stable numbers.

This should avoid wasting more time on this kind of changes in the future.

tests/test-generaldelta.t

@@ -5,9 +5,12 b' regular equivalent. Test would fail if g'
 implementation of parentdelta: third manifest revision would be fully
 inserted due to big distance from its paren revision (zero).
 
+(We disable the revlog compression to avoid the annoying instability in the chunk size that depends on the compressors implementation)
+
   $ cat << EOF >> $HGRCPATH
   > [format]
   > sparse-revlog = no
+  > revlog-compression = none
   > EOF
 
   $ hg init repo --config format.generaldelta=no --config format.usegeneraldelta=no
@@ -142,8 +145,8 b' Test revlog.optimize-delta-parent-choice'
   $ hg debugdeltachain -m
       rev      p1      p2  chain# chainlen     prev   delta
         0      -1      -1       1        1       -1    base
-        1      -1      -1       1        2        0    prev
-        2       1       0       1        3        1      p1
+        1      -1      -1       2        1       -1    base
+        2       1       0       2        2        1      p1
 
   $ hg strip -q -r . --config extensions.strip=
 
@@ -154,7 +157,7 b' Test revlog.optimize-delta-parent-choice'
   $ hg debugdeltachain -m
       rev      p1      p2  chain# chainlen     prev   delta
         0      -1      -1       1        1       -1    base
-        1      -1      -1       1        2        0    prev
+        1      -1      -1       2        1       -1    base
         2       1       0       1        2        0      p2
 
 Test that strip bundle use bundle2
@@ -266,13 +269,13 b' test maxdeltachainspan'
        46      45      -1       3       29       45      p1         58       1334       1671   1.25262      1671         0    0.00000
        47      46      -1       3       30       46      p1         58       1380       1729   1.25290      1729         0    0.00000
        48      47      -1       3       31       47      p1         58       1426       1787   1.25316      1787         0    0.00000
-       49       5      -1       4        1       -1    base        ???        316        ???   0.6????       ???         0    0.00000 (glob)
-       50      49      -1       4        2       49      p1         58        362        2??   0.7????       2??         0    0.00000 (glob)
-       51      17      -1       4        3       50    prev        3??        5??        6??   1.0????       6??         0    0.00000 (glob)
-       52      51      -1       4        4       51      p1         58        640        6??   1.0????       6??         0    0.00000 (glob)
-       53      52      -1       5        1       -1    base          0          0          0   0.00000         0         0    0.00000
-       54      53      -1       5        2       53      p1        3??        640        3??   0.5????       3??         0    0.00000 (glob)
-  $ hg clone --pull source-repo --config experimental.maxdeltachainspan=2800 relax-chain --config format.generaldelta=yes
+       49       5      -1       4        1       -1    base        317        316        317   1.00316       317         0    0.00000
+       50      49      -1       4        2       49      p1         58        362        375   1.03591       375         0    0.00000
+       51      17      -1       5        1       -1    base        595        594        595   1.00168       595         0    0.00000
+       52      51      -1       5        2       51      p1         58        640        653   1.02031       653         0    0.00000
+       53      52      -1       6        1       -1    base          0          0          0   0.00000         0         0    0.00000
+       54      53      -1       7        1       -1    base        641        640        641   1.00156       641         0    0.00000
+  $ hg clone --pull source-repo --config experimental.maxdeltachainspan=2900 relax-chain --config format.generaldelta=yes
   requesting all changes
   adding changesets
   adding manifests
@@ -332,12 +335,12 b' test maxdeltachainspan'
        46      45      -1       3       29       45      p1         58       1334       1671   1.25262      1671         0    0.00000
        47      46      -1       3       30       46      p1         58       1380       1729   1.25290      1729         0    0.00000
        48      47      -1       3       31       47      p1         58       1426       1787   1.25316      1787         0    0.00000
-       49       5      -1       4        1       -1    base        ???        316        ???   0.6????       ???         0    0.00000 (glob)
-       50      49      -1       4        2       49      p1         58        362        2??   0.7????       2??         0    0.00000 (glob)
-       51      17      -1       2       13       17      p1         58        594        739   1.24411      278?      20??    2.7???? (glob)
-       52      51      -1       5        1       -1    base        3??        640        3??   0.5????       3??         0    0.00000 (glob)
+       49       5      -1       1        7        5      p1         58        316        389   1.23101      2857      2468    6.34447
+       50      49      -1       4        1       -1    base        363        362        363   1.00276       363         0    0.00000
+       51      17      -1       5        1       -1    base        595        594        595   1.00168       595         0    0.00000
+       52      51      -1       5        2       51      p1         58        640        653   1.02031       653         0    0.00000
        53      52      -1       6        1       -1    base          0          0          0   0.00000         0         0    0.00000
-       54      53      -1       7        1       -1    base        3??        640        3??   0.5????       3??         0    0.00000 (glob)
+       54      53      -1       7        1       -1    base        641        640        641   1.00156       641         0    0.00000
   $ hg clone --pull source-repo --config experimental.maxdeltachainspan=0 noconst-chain --config format.usegeneraldelta=yes --config storage.revlog.reuse-external-delta-parent=no
   requesting all changes
   adding changesets
@@ -403,4 +406,4 b' test maxdeltachainspan'
        51      17      -1       2       13       17      p1         58        594        739   1.24411      2642      1903    2.57510
        52      51      -1       2       14       51      p1         58        640        797   1.24531      2700      1903    2.38770
        53      52      -1       4        1       -1    base          0          0          0   0.00000         0         0    0.00000
-       54      53      -1       5        1       -1    base        3??        640        3??   0.5????       3??         0    0.00000 (glob)
+       54      53      -1       5        1       -1    base        641        640        641   1.00156       641         0    0.00000