patch: turned strings with backslashes into raw strings
In Python, the backslash in an unrecognized escape sequence is left
behind, which makes '\.' the same as r'\.'. Relying on this feature is
quite brittle, IMHO.
Removed unnecessary string concatenation as well.
adding a
% default context
diff -r cf9f4ba66af2 a
--- a/a
+++ b/a
@@ -2,7 +2,7 @@
c
a
a
-b
+dd
a
a
c
% invalid --unified
abort: diff context lines count must be an integer, not 'foo'
% --unified=2
diff -r cf9f4ba66af2 a
--- a/a
+++ b/a
@@ -3,5 +3,5 @@
a
a
-b
+dd
a
a
% diff.unified=2
diff -r cf9f4ba66af2 a
--- a/a
+++ b/a
@@ -3,5 +3,5 @@
a
a
-b
+dd
a
a
% diff.unified=2 --unified=1
diff -r cf9f4ba66af2 a
--- a/a
+++ b/a
@@ -4,3 +4,3 @@
a
-b
+dd
a
% invalid diff.unified
abort: diff context lines count must be an integer, not 'foo'
% test off-by-one error with diff -p
adding a
diff -r cb9a9f314b8b a
--- a/a
+++ b/a
@@ -1,0 +1,1 @@
+b
@@ -2,0 +3,1 @@ a
+c