diff mercurial/upgrade.py @ 46335:25be21ec6c65

share: rework config options to be much clearer and easier

Recently I implemented various boolean configs which control how to behave when
there is a share-safe mismatch between source and share repository. Mismatch
means that source supports share-safe where as share does not or vice versa.

However, while discussion and documentation we realized that it's too
complicated and there are some combinations of values which makes no sense.

We decided to introduce a config option with 4 possible values which
makes controlling and understanding things easier.

The config option `share.safe-mismatch.source-{not-}safe` can have
following 4 values:

* abort (default): error out if there is mismatch
* allow: allow to work with respecting share source configuration
* {up|down}grade-abort: try to {up|down}grade, if it fails, abort
* {up|down}grade-allow: try to {up|down}grade, if it fails, continue in allow
mode


I am not sure if I can explain 3 config options which I deleted right now in
just 5 lines which is a sign of how complex they became.

No test changes demonstrate that functionality is same, only names have changed.

Differential Revision: https://phab.mercurial-scm.org/D9785

--- a/mercurial/upgrade.py	Thu Jan 14 21:34:12 2021 +0530
+++ b/mercurial/upgrade.py	Mon Jan 18 21:37:20 2021 +0530
@@ -241,7 +241,9 @@
             upgrade_op.print_post_op_messages()
 
 
-def upgrade_share_to_safe(ui, hgvfs, storevfs, current_requirements):
+def upgrade_share_to_safe(
+    ui, hgvfs, storevfs, current_requirements, mismatch_config
+):
     """Upgrades a share to use share-safe mechanism"""
     wlock = None
     store_requirements = localrepo._readrequires(storevfs, False)
@@ -253,6 +255,10 @@
     # add share-safe requirement as it will mark the share as share-safe
     diffrequires.add(requirementsmod.SHARESAFE_REQUIREMENT)
     current_requirements.add(requirementsmod.SHARESAFE_REQUIREMENT)
+    # in `allow` case, we don't try to upgrade, we just respect the source
+    # state, update requirements and continue
+    if mismatch_config == b'allow':
+        return
     try:
         wlock = lockmod.trylock(ui, hgvfs, b'wlock', 0, 0)
         # some process might change the requirement in between, re-read
@@ -271,7 +277,7 @@
         scmutil.writerequires(hgvfs, diffrequires)
         ui.warn(_(b'repository upgraded to use share-safe mode\n'))
     except error.LockError as e:
-        if ui.configbool(b'experimental', b'sharesafe-auto-upgrade-fail-error'):
+        if mismatch_config == b'upgrade-abort':
             raise error.Abort(
                 _(b'failed to upgrade share, got error: %s')
                 % stringutil.forcebytestr(e.strerror)
@@ -291,6 +297,7 @@
     hgvfs,
     sharedvfs,
     current_requirements,
+    mismatch_config,
 ):
     """Downgrades a share which use share-safe to not use it"""
     wlock = None
@@ -302,6 +309,8 @@
     source_requirements -= requirementsmod.WORKING_DIR_REQUIREMENTS
     current_requirements |= source_requirements
     current_requirements.remove(requirementsmod.SHARESAFE_REQUIREMENT)
+    if mismatch_config == b'allow':
+        return
 
     try:
         wlock = lockmod.trylock(ui, hgvfs, b'wlock', 0, 0)
@@ -319,12 +328,13 @@
         scmutil.writerequires(hgvfs, current_requirements)
         ui.warn(_(b'repository downgraded to not use share-safe mode\n'))
     except error.LockError as e:
-        # raise error right away because if downgrade failed, we cannot load
-        # the repository because it does not have complete set of requirements
-        raise error.Abort(
-            _(b'failed to downgrade share, got error: %s')
-            % stringutil.forcebytestr(e.strerror)
-        )
+        # If upgrade-abort is set, abort when upgrade fails, else let the
+        # process continue as `upgrade-allow` is set
+        if mismatch_config == b'downgrade-abort':
+            raise error.Abort(
+                _(b'failed to downgrade share, got error: %s')
+                % stringutil.forcebytestr(e.strerror)
+            )
     finally:
         if wlock:
             wlock.release()