When displaying a diff of diffs, it is possible that there is an outer
`+` before a context line. That happens when the context changed between
old and new commit. When that context line starts with a tab (after the
space that marks it as context line), our diff machinery spits out a
white-space error (space before tab), but in this case, that is
incorrect.
Work around this by detecting that situation and simply *not* printing
the space in that case.
This is slightly improper a fix because it is conceivable that an
output_prefix might be configured with *just* the right length to let
that tab jump to a different tab stop depending whether we emit that
space or not.
However, the proper fix would be relatively ugly and intrusive because
it would have to *weaken* the WS_SPACE_BEFORE_TAB option in ws.c.
Besides, we do not expose the --dual-color option in cases other than
the `branch-diff` command, which only uses a hard-coded output_prefix of
four spaces (which misses the problem by one column ;-)).
Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
---
diff.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/diff.c b/diff.c
index 98a41e88620..b98a18fe014 100644
--- a/diff.c
+++ b/diff.c
@@ -1098,6 +1098,12 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
set = diff_get_color_opt(o, DIFF_FILE_OLD);
else if (c != '+')
set = diff_get_color_opt(o, DIFF_CONTEXT);
+ /* Avoid space-before-tab warning */
+ if (c == ' ' && (len < 2 || line[1] == '\t' ||
+ line[1] == '\r' || line[1] == '\n')) {
+ line++;
+ len--;
+ }
}
emit_line_ws_markup(o, set, reset, line, len, set_sign, '+',
flags & DIFF_SYMBOL_CONTENT_WS_MASK,
--
2.17.0.409.g71698f11835
