xdiff: show non-empty lines before functions with -W

Non-empty lines before a function definition are most likely comments
for that function and thus relevant.  Include them in function context.

Such a non-empty line might also belong to the preceeding function if
there is no separating blank line.  Stop extending the context upwards
also at the next function line to make sure only one extra function body
is shown at most.

Original-patch-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t4051-diff-function-context.sh b/t/t4051-diff-function-context.sh
index 30fc5bf..2d76a97 100755 (executable)
--- a/t/t4051-diff-function-context.sh
+++ b/t/t4051-diff-function-context.sh
@@ -85,7 +85,7 @@ test_expect_success 'setup' '
 
 check_diff changed_hello 'changed function'
 
-test_expect_failure ' context includes comment' '
+test_expect_success ' context includes comment' '
        grep "^ .*Hello comment" changed_hello.diff
 '
 

diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index c2d5bd0..7778dc2 100644 (file)
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -204,6 +204,9 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
                        }
 
                        fs1 = get_func_line(xe, xecfg, NULL, i1, -1);
+                       while (fs1 > 0 && !is_empty_rec(&xe->xdf1, fs1 - 1) &&
+                              !is_func_rec(&xe->xdf1, xecfg, fs1 - 1))
+                               fs1--;
                        if (fs1 < 0)
                                fs1 = 0;
                        if (fs1 < s1) {