diffstat: be more picky when marking file as 'binary' (issue2816)

The 'Bin' marker was added to every changed file for which we could not find
any diff changes. This included binary files but also copy/renames and mode
changes. Since Mercurial regular diff format emits a 'Binary file XXX has
changed' line when fed with binary files, we use that and the usual git marker
to tell them from other cases. In particular, new empty files are no longer
reported as binary.

Still, this fix is not complete since copy/renames/mode changes are now
reported as '0' lines changes, instead of 'Bin'.

mercurial/patch.py

@@ -1787,18 +1787,17 b' def diffstatdata(lines):'
     diffre = re.compile('^diff .*-r [a-z0-9]+\s(.*)$')
 
     results = []
-    filename, adds, removes = None, 0, 0
+    filename, adds, removes, isbinary = None, 0, 0, False
 
     def addresult():
         if filename:
-            isbinary = adds == 0 and removes == 0
             results.append((filename, adds, removes, isbinary))
 
     for line in lines:
         if line.startswith('diff'):
             addresult()
             # set numbers to 0 anyway when starting new file
-            adds, removes = 0, 0
+            adds, removes, isbinary = 0, 0, False
             if line.startswith('diff --git'):
                 filename = gitre.search(line).group(1)
             elif line.startswith('diff -r'):
@@ -1808,6 +1807,9 b' def diffstatdata(lines):'
             adds += 1
         elif line.startswith('-') and not line.startswith('---'):
             removes += 1
+        elif (line.startswith('GIT binary patch') or
+              line.startswith('Binary file')):
+            isbinary = True
     addresult()
     return results
 
@@ -1832,7 +1834,7 b' def diffstat(lines, width=80, git=False)'
         return max(i * graphwidth // maxtotal, int(bool(i)))
 
     for filename, adds, removes, isbinary in stats:
-        if git and isbinary:
+        if isbinary:
             count = 'Bin'
         else:
             count = adds + removes

tests/test-diffstat.t

@@ -36,19 +36,21 b' Narrow diffstat:'
   $ hg ci -m appenda
 
   $ printf '\0' > c
-  $ hg add c
+  $ touch d
+  $ hg add c d
 
 Binary diffstat:
 
   $ hg diff --stat
-   c |    0 
+   c |  Bin 
    1 files changed, 0 insertions(+), 0 deletions(-)
 
 Binary git diffstat:
 
   $ hg diff --stat --git
    c |  Bin 
-   1 files changed, 0 insertions(+), 0 deletions(-)
+   d |    0 
+   2 files changed, 0 insertions(+), 0 deletions(-)
 
   $ hg ci -m createb
 
@@ -58,7 +60,7 b' Binary git diffstat:'
 Filename with spaces diffstat:
 
   $ hg diff --stat
-   file with spaces |    0 
+   file with spaces |  Bin 
    1 files changed, 0 insertions(+), 0 deletions(-)
 
 Filename with spaces git diffstat: