Merge lp:~nmb/bzr/247282-diff-log into lp:bzr

[Neil Martinsen-Burrell]

Document revision ranges for diff.

This adds documentation on the meaning of revision ranges for the diff command, specifically the different meaning of those ranges between log and diff.

[Vincent Ladeuil (vila)]

That's a long awaited clarification ;) This won't certainly put an end about *why* we did implement it differently, but istm that most of our users don't really care as long as it's documented.

review: Approve

[Vincent Ladeuil (vila)]

sent to pqm by email

=== modified file 'bzrlib/builtins.py'
--- bzrlib/builtins.py	2010-10-15 11:30:54 +0000
+++ bzrlib/builtins.py	2010-10-18 04:16:42 +0000
@@ -1866,6 +1866,13 @@
     "bzr diff -p1" is equivalent to "bzr diff --prefix old/:new/", and
     produces patches suitable for "patch -p1".
 
+    Note that when using the -r argument with a range of revisions, the
+    differences are computed between the two specified revisions.  That
+    is, the command does not show the changes introduced by the first 
+    revision in the range.  This differs from the interpretation of 
+    revision ranges used by "bzr log" which includes the first revision
+    in the range.
+
     :Exit values:
         1 - changed
         2 - unrepresentable changes
@@ -1889,7 +1896,11 @@
 
             bzr diff -r1..3 xxx
 
-        To see the changes introduced in revision X::
+        The changes introduced by revision 2 (equivalent to -r1..2)::
+
+            bzr diff -c2
+
+        To see the changes introduced by revision X::
         
             bzr diff -cX
 
@@ -1899,9 +1910,10 @@
 
             bzr diff -r<chosen_parent>..X
 
-        The changes introduced by revision 2 (equivalent to -r1..2)::
+        The changes between the current revision and the previous revision
+        (equivalent to -c-1 and -r-2..-1)
 
-            bzr diff -c2
+            bzr diff -r-2..
 
         Show just the differences for file NEWS::
 
 
=== modified file 'doc/en/release-notes/bzr-2.3.txt'
--- doc/en/release-notes/bzr-2.3.txt	2010-10-15 15:05:09 +0000
+++ doc/en/release-notes/bzr-2.3.txt	2010-10-18 04:16:42 +0000
@@ -58,6 +58,9 @@
 Documentation
 *************
 
+* Be more specific about the meaning of revision ranges for ``bzr diff``.
+  (Neil Martinsen-Burrell, #247282)
+
 API Changes
 ***********