[PATCH 2/3] xdiff: -W: include immediately preceding non-empty lines in context

[Vegard Nossum <vegard.nossum@oracle.com>]

When using -W to include the whole function in the diff context, you
are typically doing this to be able to review the change in its entirety
within the context of the function. It is therefore almost always
desirable to include any comments that immediately precede the function.

This also the fixes the case for C where the declaration is split across
multiple lines (where the first line of the declaration would not be
included in the output), e.g.:

	void
	dummy(void)
	{
		...
	}

We can include these lines by simply scanning upwards from the place of
the detected function start until we hit the first non-blank line.

Cc: René Scharfe <l.s.r@web.de>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
---
 xdiff/xemit.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index 8c88dbd..3a3060d 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -200,6 +200,8 @@ 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))
+				fs1--;
 			if (fs1 < 0)
 				fs1 = 0;
 			if (fs1 < s1) {
@@ -220,6 +222,8 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 			long fe1 = get_func_line(xe, xecfg, NULL,
 						 xche->i1 + xche->chg1,
 						 xe->xdf1.nrec);
+			while (fe1 > 0 && !is_empty_rec(&xe->xdf1, fe1 - 1))
+				fe1--;
 			while (fe1 > 0 && is_empty_rec(&xe->xdf1, fe1 - 1))
 				fe1--;
 			if (fe1 < 0)
-- 
2.7.4