[PATCH] log: make {diffstat} work with diff.noprefix (issue4755)

[Jun Wu]

# HG changeset patch
# User Jun Wu <quark at fb.com>
# Date 1450210516 0
#      Tue Dec 15 20:15:16 2015 +0000
# Node ID a71a4c67b0d1505c68364b13a525f2dbef886a90
# Parent  5df74b2f296df7f44a08106df4f9dd97a5aa726a
log: make {diffstat} work with diff.noprefix (issue4755)

We expect "diff --git a/$PATHA b/$PATHB" with diff.git=1. But diff.noprefix=1
breaks such expection. Fix it by reading file paths from following lines.

diff --git a/mercurial/patch.py b/mercurial/patch.py
--- a/mercurial/patch.py
+++ b/mercurial/patch.py
@@ -2482,9 +2482,11 @@
         if line.startswith('diff'):
             addresult()
             # set numbers to 0 anyway when starting new file
-            adds, removes, isbinary = 0, 0, False
+            filename, adds, removes, isbinary = None, 0, 0, False
             if line.startswith('diff --git a/'):
-                filename = gitre.search(line).group(2)
+                match = gitre.search(line)
+                if match:
+                    filename = match.group(2)
             elif line.startswith('diff -r'):
                 # format: "diff -r ... -r ... filename"
                 filename = diffre.search(line).group(1)
@@ -2492,6 +2494,11 @@
             adds += 1
         elif line.startswith('-') and not line.startswith('--- '):
             removes += 1
+        elif not filename:
+            if line[:4] in ('+++ ', '--- ') and line[4:] != '/dev/null':
+                filename = line[4:]
+            elif line.startswith('rename to '):
+                filename = line[10:]
         elif (line.startswith('GIT binary patch') or
               line.startswith('Binary file')):
             isbinary = True
diff --git a/tests/test-issue4755.t b/tests/test-issue4755.t
new file mode 100644
--- /dev/null
+++ b/tests/test-issue4755.t
@@ -0,0 +1,79 @@
+https://bz.mercurial-scm.org/4755
+
+  $ hg init
+
+Add a file
+
+  $ echo 1 > foo
+  $ hg add foo
+  $ hg ci -m 'add foo'
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1 --config diff.noprefix=1
+  1: +1/-0
+   foo |  1 +
+   1 files changed, 1 insertions(+), 0 deletions(-)
+  
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1
+  1: +1/-0
+   foo |  1 +
+   1 files changed, 1 insertions(+), 0 deletions(-)
+  
+Change a file
+
+  $ (echo 2; echo 3) > foo
+  $ hg ci -m 'change foo'
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1 --config diff.noprefix=1
+  1: +2/-1
+   foo |  3 ++-
+   1 files changed, 2 insertions(+), 1 deletions(-)
+  
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1
+  1: +2/-1
+   foo |  3 ++-
+   1 files changed, 2 insertions(+), 1 deletions(-)
+  
+Rename a file
+
+  $ hg rename foo bar
+  $ hg ci -m 'rename foo to bar'
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1 --config diff.noprefix=1
+  1: +0/-0
+   bar |  0 
+   1 files changed, 0 insertions(+), 0 deletions(-)
+  
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1
+  1: +0/-0
+   bar |  0 
+   1 files changed, 0 insertions(+), 0 deletions(-)
+  
+Rename without using hg rename
+
+  $ cp bar aha
+  $ hg remove bar
+  $ hg add aha
+  $ hg ci -m 'rename using add and remove'
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1 --config diff.noprefix=1
+  2: +2/-2
+   aha |  2 ++
+   bar |  2 --
+   2 files changed, 2 insertions(+), 2 deletions(-)
+  
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1
+  2: +2/-2
+   aha |  2 ++
+   bar |  2 --
+   2 files changed, 2 insertions(+), 2 deletions(-)
+  
+Delete a file
+
+  $ hg remove aha
+  $ hg ci -m 'remove aha'
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1 --config diff.noprefix=1
+  1: +0/-2
+   aha |  2 --
+   1 files changed, 0 insertions(+), 2 deletions(-)
+  
+  $ hg log -r . --stat -T '{diffstat}\n' --config diff.git=1
+  1: +0/-2
+   aha |  2 --
+   1 files changed, 0 insertions(+), 2 deletions(-)
+