Changes involving only blank lines are hidden with --ignore-blank-lines,
unless they appear in the context lines of other changes. This is
handled by xdl_get_hunk() for context added by --inter-hunk-context, -u
and -U.
Function context for -W and --function-context added by xdl_emit_diff()
doesn't pay attention to such ignored changes; it relies fully on
xdl_get_hunk() and shows just the post-image of ignored changes
appearing in function context. That's inconsistent and confusing.
Improve the result of using --ignore-blank-lines and --function-context
together by fully showing ignored changes if they happen to fall within
function context.
Signed-off-by: René Scharfe <l.s.r@xxxxxx>
---
t/t4015-diff-whitespace.sh | 6 +-----
xdiff/xemit.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index eadaf57262..5888ae5ed3 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -2025,11 +2025,6 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
test_cmp expected actual
'
-# Note that the "6" in the expected hunk header below is funny, since we only
-# show 5 lines (the missing one was blank and thus ignored). This is how
-# --ignore-blank-lines behaves even without --function-context, and this test
-# is just checking the interaction of the two features. Don't take it as an
-# endorsement of that output.
test_expect_success 'combine --ignore-blank-lines with --function-context' '
test_write_lines 1 "" 2 3 4 5 >a &&
test_write_lines 1 2 3 4 >b &&
@@ -2039,6 +2034,7 @@ test_expect_success 'combine --ignore-blank-lines with --function-context' '
cat <<-\EOF >expect &&
@@ -1,6 +1,4 @@
1
+ -
2
3
4
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index 30713ae9a9..9d7d6c5087 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -172,10 +172,12 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
struct func_line func_line = { 0 };
for (xch = xscr; xch; xch = xche->next) {
+ xdchange_t *xchp = xch;
xche = xdl_get_hunk(&xch, xecfg);
if (!xch)
break;
+pre_context_calculation:
s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
@@ -212,6 +214,21 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
if (fs1 < s1) {
s2 = XDL_MAX(s2 - (s1 - fs1), 0);
s1 = fs1;
+
+ /*
+ * Did we extend context upwards into an
+ * ignored change?
+ */
+ while (xchp != xch &&
+ xchp->i1 + xchp->chg1 <= s1 &&
+ xchp->i2 + xchp->chg2 <= s2)
+ xchp = xchp->next;
+
+ /* If so, show it after all. */
+ if (xchp != xch) {
+ xch = xchp;
+ goto pre_context_calculation;
+ }
}
}
--
2.24.0
