merge: use labels in prompts to the user

Now that we persist the labels, we can consistently use the labels in
prompts for the user without risk of confusion. This changes a huge amount
of command output:

This means that merge prompts like:
  no tool found to merge a
  keep (l)ocal, take (o)ther, or leave (u)nresolved? u
and
  remote changed a which local deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
become:
  no tool found to merge a
  keep (l)ocal [working copy], take (o)ther [destination], or leave (u)nresolved? u
and
  remote [source] changed a which local [dest] deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
where "working copy" and "destination" were supplied by the command that
requested the merge as labels for conflict markers, and thus should be
human-friendly.

mercurial/filemerge.py

@@ -230,50 +230,56 b' def _matcheol(file, origfile):'
                 util.writefile(file, newdata)
 
 @internaltool('prompt', nomerge)
-def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf):
+def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Asks the user which of the local `p1()` or the other `p2()` version to
     keep as the merged version."""
     ui = repo.ui
     fd = fcd.path()
 
+    prompts = partextras(labels)
+    prompts['fd'] = fd
     try:
         if fco.isabsent():
             index = ui.promptchoice(
-                _("local changed %s which remote deleted\n"
+                _("local%(l)s changed %(fd)s which remote%(o)s deleted\n"
                   "use (c)hanged version, (d)elete, or leave (u)nresolved?"
-                  "$$ &Changed $$ &Delete $$ &Unresolved") % fd, 2)
+                  "$$ &Changed $$ &Delete $$ &Unresolved") % prompts, 2)
             choice = ['local', 'other', 'unresolved'][index]
         elif fcd.isabsent():
             index = ui.promptchoice(
-                _("remote changed %s which local deleted\n"
+                _("remote%(o)s changed %(fd)s which local%(l)s deleted\n"
                   "use (c)hanged version, leave (d)eleted, or "
                   "leave (u)nresolved?"
-                  "$$ &Changed $$ &Deleted $$ &Unresolved") % fd, 2)
+                  "$$ &Changed $$ &Deleted $$ &Unresolved") % prompts, 2)
             choice = ['other', 'local', 'unresolved'][index]
         else:
             index = ui.promptchoice(
-                _("no tool found to merge %s\n"
-                  "keep (l)ocal, take (o)ther, or leave (u)nresolved?"
-                  "$$ &Local $$ &Other $$ &Unresolved") % fd, 2)
+                _("no tool found to merge %(fd)s\n"
+                  "keep (l)ocal%(l)s, take (o)ther%(o)s, or leave (u)nresolved?"
+                  "$$ &Local $$ &Other $$ &Unresolved") % prompts, 2)
             choice = ['local', 'other', 'unresolved'][index]
 
         if choice == 'other':
-            return _iother(repo, mynode, orig, fcd, fco, fca, toolconf)
+            return _iother(repo, mynode, orig, fcd, fco, fca, toolconf,
+                           labels)
         elif choice == 'local':
-            return _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf)
+            return _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf,
+                           labels)
         elif choice == 'unresolved':
-            return _ifail(repo, mynode, orig, fcd, fco, fca, toolconf)
+            return _ifail(repo, mynode, orig, fcd, fco, fca, toolconf,
+                          labels)
     except error.ResponseExpected:
         ui.write("\n")
-        return _ifail(repo, mynode, orig, fcd, fco, fca, toolconf)
+        return _ifail(repo, mynode, orig, fcd, fco, fca, toolconf,
+                      labels)
 
 @internaltool('local', nomerge)
-def _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf):
+def _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Uses the local `p1()` version of files as the merged version."""
     return 0, fcd.isabsent()
 
 @internaltool('other', nomerge)
-def _iother(repo, mynode, orig, fcd, fco, fca, toolconf):
+def _iother(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Uses the other `p2()` version of files as the merged version."""
     if fco.isabsent():
         # local changed, remote deleted -- 'deleted' picked
@@ -285,7 +291,7 b' def _iother(repo, mynode, orig, fcd, fco'
     return 0, deleted
 
 @internaltool('fail', nomerge)
-def _ifail(repo, mynode, orig, fcd, fco, fca, toolconf):
+def _ifail(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """
     Rather than attempting to merge files that were modified on both
     branches, it marks them as unresolved. The resolve command must be
@@ -537,6 +543,22 b' def _formatlabels(repo, fcd, fco, fca, l'
         newlabels.append(_formatconflictmarker(repo, ca, tmpl, labels[2], pad))
     return newlabels
 
+def partextras(labels):
+    """Return a dictionary of extra labels for use in prompts to the user
+
+    Intended use is in strings of the form "(l)ocal%(l)s".
+    """
+    if labels is None:
+        return {
+            "l": "",
+            "o": "",
+        }
+
+    return {
+        "l": " [%s]" % labels[0],
+        "o": " [%s]" % labels[1],
+    }
+
 def _filemerge(premerge, repo, mynode, orig, fcd, fco, fca, labels=None):
     """perform a 3-way merge in the working directory
 
@@ -588,7 +610,7 b' def _filemerge(premerge, repo, mynode, o'
     toolconf = tool, toolpath, binary, symlink
 
     if mergetype == nomerge:
-        r, deleted = func(repo, mynode, orig, fcd, fco, fca, toolconf)
+        r, deleted = func(repo, mynode, orig, fcd, fco, fca, toolconf, labels)
         return True, r, deleted
 
     if premerge:

mercurial/merge.py

@@ -1535,11 +1535,13 b' def update(repo, node, branchmerge, forc'
         if '.hgsubstate' in actionbyfile:
             f = '.hgsubstate'
             m, args, msg = actionbyfile[f]
+            prompts = filemerge.partextras(labels)
+            prompts['f'] = f
             if m == 'cd':
                 if repo.ui.promptchoice(
-                    _("local changed %s which remote deleted\n"
+                    _("local%(l)s changed %(f)s which remote%(o)s deleted\n"
                       "use (c)hanged version or (d)elete?"
-                      "$$ &Changed $$ &Delete") % f, 0):
+                      "$$ &Changed $$ &Delete") % prompts, 0):
                     actionbyfile[f] = ('r', None, "prompt delete")
                 elif f in p1:
                     actionbyfile[f] = ('am', None, "prompt keep")
@@ -1549,9 +1551,9 b' def update(repo, node, branchmerge, forc'
                 f1, f2, fa, move, anc = args
                 flags = p2[f2].flags()
                 if repo.ui.promptchoice(
-                    _("remote changed %s which local deleted\n"
+                    _("remote%(o)s changed %(f)s which local%(l)s deleted\n"
                       "use (c)hanged version or leave (d)eleted?"
-                      "$$ &Changed $$ &Deleted") % f, 0) == 0:
+                      "$$ &Changed $$ &Deleted") % prompts, 0) == 0:
                     actionbyfile[f] = ('g', (flags, False), "prompt recreating")
                 else:
                     del actionbyfile[f]

tests/failfilemerge.py

@@ -9,7 +9,7 b' from mercurial import ('
 )
 
 def failfilemerge(filemergefn,
-        premerge, repo, mynode, orig, fcd, fco, fca, labels=None):
+                  premerge, repo, mynode, orig, fcd, fco, fca, labels=None):
     raise error.Abort("^C")
     return filemergefn(premerge, repo, mynode, orig, fcd, fco, fca, labels)
 

tests/test-copy-move-merge.t

@@ -85,7 +85,7 b' Test disabling copy tracing'
   > c
   > EOF
   rebasing 2:add3f11052fa "other" (tip)
-  remote changed a which local deleted
+  remote [source] changed a which local [dest] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
 
   $ cat b

tests/test-largefiles-update.t

@@ -611,7 +611,7 b' the 1st commit of resuming.'
   > EOF
   rebasing 1:72518492caa6 "#1"
   rebasing 4:07d6153b5c04 "#4"
-  local changed .hglf/large1 which remote deleted
+  local [dest] changed .hglf/large1 which remote [source] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? c
 
   $ hg diff -c "tip~1" --nodates .hglf/large1 | grep '^[+-][0-9a-z]'

tests/test-merge-changedelete.t

@@ -717,9 +717,9 b' Non-interactive linear update'
   $ echo changed >> file1
   $ hg rm file2
   $ hg update 1 -y
-  local changed file1 which remote deleted
+  local [working copy] changed file1 which remote [destination] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? u
-  remote changed file2 which local deleted
+  remote [destination] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? u
   1 files updated, 0 files merged, 0 files removed, 2 files unresolved
   use 'hg resolve' to retry unresolved file merges
@@ -893,9 +893,9 b' Force prompts with no input'
   $ echo changed >> file1
   $ hg rm file2
   $ hg update 1 --config ui.interactive=True --tool :prompt
-  local changed file1 which remote deleted
+  local [working copy] changed file1 which remote [destination] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? 
-  remote changed file2 which local deleted
+  remote [destination] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? 
   1 files updated, 0 files merged, 0 files removed, 2 files unresolved
   use 'hg resolve' to retry unresolved file merges
@@ -943,9 +943,9 b' Choose to merge all files'
   $ echo changed >> file1
   $ hg rm file2
   $ hg update 1 --tool :merge3
-  local changed file1 which remote deleted
+  local [working copy] changed file1 which remote [destination] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? u
-  remote changed file2 which local deleted
+  remote [destination] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? u
   1 files updated, 0 files merged, 0 files removed, 2 files unresolved
   use 'hg resolve' to retry unresolved file merges
@@ -999,9 +999,9 b' Test transitions between different merge'
   (status identical)
   
   === :other -> :prompt ===
-  local changed file1 which remote deleted
+  local [working copy] changed file1 which remote [destination] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? 
-  remote changed file2 which local deleted
+  remote [destination] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? 
   --- diff of status ---
   (status identical)
@@ -1026,9 +1026,9 b' Test transitions between different merge'
   (status identical)
   
   === :local -> :prompt ===
-  local changed file1 which remote deleted
+  local [working copy] changed file1 which remote [destination] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? 
-  remote changed file2 which local deleted
+  remote [destination] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? 
   --- diff of status ---
   (status identical)
@@ -1043,9 +1043,9 b' Test transitions between different merge'
   (status identical)
   
   === :fail -> :prompt ===
-  local changed file1 which remote deleted
+  local [working copy] changed file1 which remote [destination] deleted
   use (c)hanged version, (d)elete, or leave (u)nresolved? 
-  remote changed file2 which local deleted
+  remote [destination] changed file2 which local [working copy] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? 
   --- diff of status ---
   (status identical)

tests/test-merge-types.t

@@ -173,7 +173,7 b' Update to link with local change should '
   (couldn't find merge tool hgmerge|tool hgmerge can't handle symlinks) (re)
   picked tool ':prompt' for a (binary False symlink True changedelete False)
   no tool found to merge a
-  keep (l)ocal, take (o)ther, or leave (u)nresolved? u
+  keep (l)ocal [working copy], take (o)ther [destination], or leave (u)nresolved? u
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges
   1 other heads for branch "default"

tests/test-rebase-newancestor.t

@@ -135,7 +135,7 b' Full rebase all the way back from branch'
   note: rebase of 1:1d1a643d390e created no changes to commit
   rebasing 2:ec2c14fb2984 "dev: f-dev stuff"
   rebasing 4:4b019212aaf6 "dev: merge default"
-  remote changed f-default which local deleted
+  remote [source] changed f-default which local [dest] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
   rebasing 6:9455ee510502 "dev: merge default"
   saved backup bundle to $TESTTMP/ancestor-merge/.hg/strip-backup/1d1a643d390e-43e9e04b-backup.hg (glob)
@@ -164,7 +164,7 b' Grafty cherry picking rebasing:'
   > EOF
   rebasing 2:ec2c14fb2984 "dev: f-dev stuff"
   rebasing 4:4b019212aaf6 "dev: merge default"
-  remote changed f-default which local deleted
+  remote [source] changed f-default which local [dest] deleted
   use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
   rebasing 6:9455ee510502 "dev: merge default"
   saved backup bundle to $TESTTMP/ancestor-merge-2/.hg/strip-backup/ec2c14fb2984-62d0b222-backup.hg (glob)

tests/test-subrepo-missing.t

@@ -62,7 +62,7 b' delete .hgsubstate and update'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ rm .hgsubstate
   $ hg up 0
-  remote changed .hgsubstate which local deleted
+  remote [destination] changed .hgsubstate which local [working copy] deleted
   use (c)hanged version or leave (d)eleted? c
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg st