changeset 28782:f736f98e16ca

mpatch: unify mpatchError (issue5182)

The pure version was mpatch was throwing struct.error or ValueError
for errors, whereas the C version was throwing an "mpatch.mpatchError".

Introducing an mpatch.mpatchError into pure and using it consistently
is fairly easy, but the actual form for it is mercurial.mpatch.mpatchError,
so with this commit, we change the C implementation to match the naming
convention too.

--- a/mercurial/mpatch.c	Wed Mar 30 22:01:47 2016 +0000
+++ b/mercurial/mpatch.c	Thu Mar 31 02:05:28 2016 +0000
@@ -404,7 +404,8 @@
 	if (m == NULL)
 		return NULL;
 
-	mpatch_Error = PyErr_NewException("mpatch.mpatchError", NULL, NULL);
+	mpatch_Error = PyErr_NewException("mercurial.mpatch.mpatchError",
+					  NULL, NULL);
 	Py_INCREF(mpatch_Error);
 	PyModule_AddObject(m, "mpatchError", mpatch_Error);
 
@@ -415,6 +416,7 @@
 initmpatch(void)
 {
 	Py_InitModule3("mpatch", methods, mpatch_doc);
-	mpatch_Error = PyErr_NewException("mpatch.mpatchError", NULL, NULL);
+	mpatch_Error = PyErr_NewException("mercurial.mpatch.mpatchError",
+					  NULL, NULL);
 }
 #endif

--- a/mercurial/pure/mpatch.py	Wed Mar 30 22:01:47 2016 +0000
+++ b/mercurial/pure/mpatch.py	Thu Mar 31 02:05:28 2016 +0000
@@ -12,6 +12,10 @@
 
 StringIO = cStringIO.StringIO
 
+class mpatchError(Exception):
+    """error raised when a delta cannot be decoded
+    """
+
 # This attempts to apply a series of patches in time proportional to
 # the total size of the patches, rather than patches * len(text). This
 # means rather than shuffling strings around, we shuffle around
@@ -84,7 +88,10 @@
         last = 0
         while pos < end:
             m.seek(pos)
-            p1, p2, l = struct.unpack(">lll", m.read(12))
+            try:
+                p1, p2, l = struct.unpack(">lll", m.read(12))
+            except struct.error:
+                raise mpatchError("patch cannot be decoded")
             _pull(new, frags, p1 - last) # what didn't change
             _pull([], frags, p2 - p1)    # what got deleted
             new.append((l, pos + 12))   # what got added
@@ -114,7 +121,7 @@
         outlen += length
 
     if bin != binend:
-        raise ValueError("patch cannot be decoded")
+        raise mpatchError("patch cannot be decoded")
 
     outlen += orig - last
     return outlen

--- a/tests/test-revlog.t	Wed Mar 30 22:01:47 2016 +0000
+++ b/tests/test-revlog.t	Thu Mar 31 02:05:28 2016 +0000
@@ -11,5 +11,5 @@
      rev    offset  length  delta linkrev nodeid       p1           p2
        0         0      19     -1       2 99e0332bd498 000000000000 000000000000
        1        19      12      0       3 6674f57a23d8 99e0332bd498 000000000000
-  $ hg debugdata a.i 1 2>&1 | grep decoded
-  mpatch.mpatchError: patch cannot be decoded
+  $ hg debugdata a.i 1 2>&1 | egrep 'Error:.*decoded'
+  mercurial.mpatch.mpatchError: patch cannot be decoded