builtin-mv.c: check for unversionned files before looking at the destination.

The previous code was failing in the case where one moves an
unversionned file to an existing destination, with mv -f: the
"existing destination" was checked first, and the error was cancelled
by the force flag.

We now check the unrecoverable error first, which fixes the bug.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-mv.c

@@ -162,7 +162,9 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 				}
 				argc += last - first;
 			}
-		} else if (lstat(dst, &st) == 0) {
+		} else if (cache_name_pos(src, length) < 0)
+			bad = "not under version control";
+		else if (lstat(dst, &st) == 0) {
 			bad = "destination exists";
 			if (force) {
 				/*
@@ -177,9 +179,7 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 				} else
 					bad = "Cannot overwrite";
 			}
-		} else if (cache_name_pos(src, length) < 0)
-			bad = "not under version control";
-		else if (string_list_has_string(&src_for_dst, dst))
+		} else if (string_list_has_string(&src_for_dst, dst))
 			bad = "multiple sources for the same target";
 		else
 			string_list_insert(dst, &src_for_dst);

t/t7001-mv.sh

@@ -58,7 +58,7 @@ test_expect_success \
      test ! -f path0/untracked1 &&
      test ! -f path0/untracked2'
 
-test_expect_failure \
+test_expect_success \
     'checking -f on untracked file with existing target' \
     'touch path0/untracked1 &&
      git mv -f untracked1 path0