D6440: fix: let fixer tools inherit hg's cwd so they can look at the working copy

[hooper (Danny Hooper)]

hooper created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  This lets fixer tools do things like find configuration files, with the caveat
  that they'll only see the version of that file in the working copy, regardless
  of what revisions are being fixed.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D6440

AFFECTED FILES
  hgext/fix.py
  tests/test-fix.t

CHANGE DETAILS

diff --git a/tests/test-fix.t b/tests/test-fix.t
--- a/tests/test-fix.t
+++ b/tests/test-fix.t
@@ -1264,3 +1264,37 @@
 
   $ cd ..
 
+We run fixer tools in the cwd so they can look for config files or other
+important things in the working directory. This does NOT mean we are
+reconstructing a working copy of every revision being fixed; we're just giving
+the tool knowledge of the cwd in case it can do something reasonable with that.
+
+  $ hg init subprocesscwd
+  $ cd subprocesscwd
+
+  $ cat >> .hg/hgrc <<EOF
+  > [fix]
+  > printcwd:command = pwd
+  > printcwd:pattern = path:foo/bar
+  > EOF
+
+  $ mkdir foo
+  $ printf "bar\n" > foo/bar
+  $ hg commit -Aqm blah
+
+  $ hg fix -w -r . foo/bar
+  $ hg cat -r tip foo/bar
+  $TESTTMP/subprocesscwd
+  $ cat foo/bar
+  $TESTTMP/subprocesscwd
+
+  $ cd foo
+
+  $ hg fix -w -r . bar
+  $ hg cat -r tip bar
+  $TESTTMP/subprocesscwd/foo
+  $ cat bar
+  $TESTTMP/subprocesscwd/foo
+
+  $ cd ../..
+
diff --git a/hgext/fix.py b/hgext/fix.py
--- a/hgext/fix.py
+++ b/hgext/fix.py
@@ -102,6 +102,13 @@
     mapping fixer tool names to lists of metadata values returned from
     executions that modified a file. This aggregates the same metadata
     previously passed to the "postfixfile" hook.
+
+Fixer tools are run the in same working directory as the :hg:`fix` command. This
+allows them to read configuration files from the working copy, or even write to
+the working copy. The working copy is not updated to match the revision being
+fixed. In fact, several revisions may be fixed in parallel. Writes to the
+working copy are not amended into the revision being fixed; fixer tools should
+always write fixed file content back to stdout as documented above.
 """
 
 from __future__ import absolute_import
@@ -233,7 +240,7 @@
             for rev, path in items:
                 ctx = repo[rev]
                 olddata = ctx[path].data()
-                metadata, newdata = fixfile(ui, opts, fixers, ctx, path,
+                metadata, newdata = fixfile(ui, repo, opts, fixers, ctx, path,
                                             basectxs[rev])
                 # Don't waste memory/time passing unchanged content back, but
                 # produce one result per item either way.
@@ -530,16 +537,17 @@
                 basectxs[rev].add(pctx)
     return basectxs
 
-def fixfile(ui, opts, fixers, fixctx, path, basectxs):
+def fixfile(ui, repo, opts, fixers, fixctx, path, basectxs):
     """Run any configured fixers that should affect the file in this context
 
     Returns the file content that results from applying the fixers in some order
     starting with the file's content in the fixctx. Fixers that support line
     ranges will affect lines that have changed relative to any of the basectxs
     (i.e. they will only avoid lines that are common to all basectxs).
 
     A fixer tool's stdout will become the file's new content if and only if it
-    exits with code zero.
+    exits with code zero. The fixer tool's working directory is inherited from
+    this process.
     """
     metadata = {}
     newdata = fixctx[path].data()
@@ -553,7 +561,7 @@
             proc = subprocess.Popen(
                 procutil.tonativestr(command),
                 shell=True,
-                cwd=procutil.tonativestr(b'/'),
+                cwd=None,
                 stdin=subprocess.PIPE,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE)



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Cc: mercurial-devel