phabricator: change "readpatch" to be more flexible

Previously, `readpatch` and `querydrev` take a same `params` and `stack`
parameters. This patch changes `readpatch` so it takes the output of
`querydrev`, not the input of `querydrev`. This makes the code more
flexible and cleaner.

Differential Revision: https://phab.mercurial-scm.org/D124

contrib/phabricator.py

@@ -635,15 +635,12 b' def getdiffmeta(diff):'
             meta[r'parent'] = commit[r'parents'][0]
     return meta or {}
 
-def readpatch(repo, params, write, stack=False):
+def readpatch(repo, drevs, write):
     """generate plain-text patch readable by 'hg import'
 
-    write is usually ui.write. params is passed to "differential.query". If
-    stack is True, also write dependent patches.
+    write is usually ui.write. drevs is what "querydrev" returns, results of
+    "differential.query".
     """
-    # Differential Revisions
-    drevs = querydrev(repo, params, stack)
-
     # Prefetch hg:meta property for all diffs
     diffids = sorted(set(max(int(v) for v in drev[r'diffs']) for drev in drevs))
     diffs = callconduit(repo, 'differential.querydiffs', {'ids': diffids})
@@ -683,4 +680,5 b' def phabread(ui, repo, revid, **opts):'
         revid = int(revid.split('/')[-1].replace('D', ''))
     except ValueError:
         raise error.Abort(_('invalid Revision ID: %s') % revid)
-    readpatch(repo, {'ids': [revid]}, ui.write, opts.get('stack'))
+    drevs = querydrev(repo, {'ids': [revid]}, opts.get('stack'))
+    readpatch(repo, drevs, ui.write)