Check that git patches only touch files under root

mercurial/patch.py

@@ -1039,9 +1039,12 b' def applydiff(ui, fp, changed, strip=1, '
                 continue
         elif state == 'git':
             gitpatches = values
+            cwd = os.getcwd()
             for gp in gitpatches:
                 if gp.op in ('COPY', 'RENAME'):
-                    copyfile(gp.oldpath, gp.path)
+                    src, dst = [util.canonpath(cwd, cwd, x)
+                                for x in [gp.oldpath, gp.path]]
+                    copyfile(src, dst)
                 changed[gp.path] = (gp.op, gp)
         else:
             raise util.Abort(_('unsupported parser state: %s') % state)

tests/test-import

@@ -261,3 +261,15 b' EOF'
 hg status
 cat a
 cd ..
+
+echo % 'test paths outside repo root'
+mkdir outside
+touch outside/foo
+hg init inside
+cd inside
+hg import - <<EOF
+diff --git a/a b/b
+rename from ../outside/foo
+rename to bar
+EOF
+cd ..

tests/test-import.out

@@ -260,3 +260,6 b' a'
 adding a
 applying patch from stdin
 bb
+% test paths outside repo root
+applying patch from stdin
+abort: ../outside/foo not under root