extdiff: refactor logic to diff revs of versions of files

Now that code for both cases, diffing patches or files is in separate function,
it will be better to refactor them more and understand.

Differential Revision: https://phab.mercurial-scm.org/D8687

hgext/extdiff.py

@@ -382,54 +382,21 b' def diffpatch(ui, repo, node1a, node2, t'
     return 1
 
 
-def dodiff(ui, repo, cmdline, pats, opts, guitool=False):
-    '''Do the actual diff:
-
-    - copy to a temp structure if diffing 2 internal revisions
-    - copy to a temp structure if diffing working revision with
-      another one and more than 1 file is changed
-    - just invoke the diff for a single file in the working dir
-    '''
-
-    cmdutil.check_at_most_one_arg(opts, b'rev', b'change')
-    revs = opts.get(b'rev')
-    change = opts.get(b'change')
-    do3way = b'$parent2' in cmdline
-
-    if change:
-        ctx2 = scmutil.revsingle(repo, change, None)
-        ctx1a, ctx1b = ctx2.p1(), ctx2.p2()
-    else:
-        ctx1a, ctx2 = scmutil.revpair(repo, revs)
-        if not revs:
-            ctx1b = repo[None].p2()
-        else:
-            ctx1b = repo[nullid]
-
-    perfile = opts.get(b'per_file')
-    confirm = opts.get(b'confirm')
-
-    node1a = ctx1a.node()
-    node1b = ctx1b.node()
-    node2 = ctx2.node()
-
-    # Disable 3-way merge if there is only one parent
-    if do3way:
-        if node1b == nullid:
-            do3way = False
+def diffrevs(
+    ui,
+    repo,
+    node1a,
+    node1b,
+    node2,
+    matcher,
+    tmproot,
+    cmdline,
+    do3way,
+    guitool,
+    opts,
+):
 
     subrepos = opts.get(b'subrepos')
-
-    matcher = scmutil.match(repo[node2], pats, opts)
-
-    if opts.get(b'patch'):
-        if subrepos:
-            raise error.Abort(_(b'--patch cannot be used with --subrepos'))
-        if perfile:
-            raise error.Abort(_(b'--patch cannot be used with --per-file'))
-        if node2 is None:
-            raise error.Abort(_(b'--patch requires two revisions'))
-    else:
         st = repo.status(node1a, node2, matcher, listsubrepos=subrepos)
         mod_a, add_a, rem_a = set(st.modified), set(st.added), set(st.removed)
         if do3way:
@@ -445,23 +412,13 b' def dodiff(ui, repo, cmdline, pats, opts'
         common = modadd | rem_a | rem_b
         if not common:
             return 0
-
-    tmproot = pycompat.mkdtemp(prefix=b'extdiff.')
-    try:
-        if opts.get(b'patch'):
-            return diffpatch(
-                ui, repo, node1a, node2, tmproot, matcher, cmdline, do3way
-            )
-
         # Always make a copy of node1a (and node1b, if applicable)
         dir1a_files = mod_a | rem_a | ((mod_b | add_b) - add_a)
         dir1a = snapshot(ui, repo, dir1a_files, node1a, tmproot, subrepos)[0]
         rev1a = b'@%d' % repo[node1a].rev()
         if do3way:
             dir1b_files = mod_b | rem_b | ((mod_a | add_a) - add_b)
-            dir1b = snapshot(ui, repo, dir1b_files, node1b, tmproot, subrepos)[
-                0
-            ]
+        dir1b = snapshot(ui, repo, dir1b_files, node1b, tmproot, subrepos)[0]
             rev1b = b'@%d' % repo[node1b].rev()
         else:
             dir1b = None
@@ -480,9 +437,7 b' def dodiff(ui, repo, cmdline, pats, opts'
             # the working dir in this case (because the other cases
             # are: diffing 2 revisions or single file -- in which case
             # the file is already directly passed to the diff tool).
-            dir2, fnsandstat = snapshot(
-                ui, repo, modadd, None, tmproot, subrepos
-            )
+        dir2, fnsandstat = snapshot(ui, repo, modadd, None, tmproot, subrepos)
         else:
             # This lets the diff tool open the changed file directly
             dir2 = b''
@@ -508,7 +463,7 b' def dodiff(ui, repo, cmdline, pats, opts'
             dir2 = os.path.join(dir2root, dir2, common_file)
             label2 = common_file + rev2
 
-        if not perfile:
+    if not opts.get(b'per_file'):
             # Run the external tool on the 2 temp directories or the patches
             cmdline = formatcmdline(
                 cmdline,
@@ -521,9 +476,7 b' def dodiff(ui, repo, cmdline, pats, opts'
                 child=dir2,
                 clabel=label2,
             )
-            ui.debug(
-                b'running %r in %s\n' % (pycompat.bytestr(cmdline), tmproot)
-            )
+        ui.debug(b'running %r in %s\n' % (pycompat.bytestr(cmdline), tmproot))
             ui.system(cmdline, cwd=tmproot, blockedtag=b'extdiff')
         else:
             # Run the external tool once for each pair of files
@@ -533,7 +486,7 b' def dodiff(ui, repo, cmdline, pats, opts'
                 ui,
                 guitool=guitool,
                 do3way=do3way,
-                confirm=confirm,
+            confirm=opts.get(b'confirm'),
                 commonfiles=common,
                 tmproot=tmproot,
                 dir1a=dir1a,
@@ -566,6 +519,72 b' def dodiff(ui, repo, cmdline, pats, opts'
                 util.copyfile(copy_fn, working_fn)
 
         return 1
+
+
+def dodiff(ui, repo, cmdline, pats, opts, guitool=False):
+    '''Do the actual diff:
+
+    - copy to a temp structure if diffing 2 internal revisions
+    - copy to a temp structure if diffing working revision with
+      another one and more than 1 file is changed
+    - just invoke the diff for a single file in the working dir
+    '''
+
+    cmdutil.check_at_most_one_arg(opts, b'rev', b'change')
+    revs = opts.get(b'rev')
+    change = opts.get(b'change')
+    do3way = b'$parent2' in cmdline
+
+    if change:
+        ctx2 = scmutil.revsingle(repo, change, None)
+        ctx1a, ctx1b = ctx2.p1(), ctx2.p2()
+    else:
+        ctx1a, ctx2 = scmutil.revpair(repo, revs)
+        if not revs:
+            ctx1b = repo[None].p2()
+        else:
+            ctx1b = repo[nullid]
+
+    node1a = ctx1a.node()
+    node1b = ctx1b.node()
+    node2 = ctx2.node()
+
+    # Disable 3-way merge if there is only one parent
+    if do3way:
+        if node1b == nullid:
+            do3way = False
+
+    matcher = scmutil.match(repo[node2], pats, opts)
+
+    if opts.get(b'patch'):
+        if opts.get(b'subrepos'):
+            raise error.Abort(_(b'--patch cannot be used with --subrepos'))
+        if opts.get(b'per_file'):
+            raise error.Abort(_(b'--patch cannot be used with --per-file'))
+        if node2 is None:
+            raise error.Abort(_(b'--patch requires two revisions'))
+
+    tmproot = pycompat.mkdtemp(prefix=b'extdiff.')
+    try:
+        if opts.get(b'patch'):
+            return diffpatch(
+                ui, repo, node1a, node2, tmproot, matcher, cmdline, do3way
+            )
+
+        return diffrevs(
+            ui,
+            repo,
+            node1a,
+            node1b,
+            node2,
+            matcher,
+            tmproot,
+            cmdline,
+            do3way,
+            guitool,
+            opts,
+        )
+
     finally:
         ui.note(_(b'cleaning up temp directory\n'))
         shutil.rmtree(tmproot)