commands.import: accept a prefix option The --prefix option is meant to be relative to the root rather than the current working directory. This is for consistency with the rest of 'hg import' -- paths in patches are otherwise considered to be relative to the root. In upcoming patches we'll hook this option up to the patch functions. --exact with --prefix is currently disallowed because I can't really come up with sensible semantics for it, especially when only part of the patch is preserved.

--- a/tests/test-import-bypass.t	Tue Mar 10 11:01:10 2015 -0700
+++ b/tests/test-import-bypass.t	Fri Mar 06 22:56:19 2015 -0800
@@ -112,6 +112,9 @@
   $ hg import --bypass --similarity 50 ../test.diff
   abort: cannot use --similarity with --bypass
   [255]
+  $ hg import --exact --prefix dir/ ../test.diff
+  abort: cannot use --exact with --prefix
+  [255]
 
 Test commit editor
 (this also tests that editor is invoked, if the patch doesn't contain