[PATCH 7/7] diff.c: add --color-moved-ignore-space-delta option
This marks moved code still as blocks when their indentation level changes uniformly.
Signed-off-by: Stefan Beller <sbeller@google.com>
---
Documentation/diff-options.txt | 4 ++
diff.c | 83 +++++++++++++++++++++++++++++++---
diff.h | 2 +
t/t4015-diff-whitespace.sh | 54 ++++++++++++++++++++++
4 files changed, 137 insertions(+), 6 deletions(-)
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 7b2527b9a1..facdbc8f95 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -304,6 +304,10 @@ dimmed_zebra::
Ignore whitespace when comparing lines when performing the move
detection for --color-moved. This ignores differences even if
one line has whitespace where the other line has none.
+--color-moved-[no-]ignore-space-prefix-delta::
+ Ignores whitespace when comparing lines when performing the move
+ detection for --color-moved. This ignores uniform differences
+ of white space at the beginning lines in moved blocks.
--word-diff[=<mode>]::
Show a word diff, using the <mode> to delimit changed words.
diff --git a/diff.c b/diff.c
index b5819dd538..1227a4d2a8 100644
--- a/diff.c
+++ b/diff.c
@@ -709,6 +709,31 @@ struct moved_entry {
struct moved_entry *next_line;
};
+struct ws_delta {
+ char *string; /* The prefix delta, which is the same in the block */
+ int direction; /* adding or removing the line? */
+ int missmatch; /* in the remainder */
+};
+#define WS_DELTA_INIT { NULL, 0, 0 }
+
+static void compute_ws_delta(const struct emitted_diff_symbol *a,
+ const struct emitted_diff_symbol *b,
+ struct ws_delta *out)
+{
+ const struct emitted_diff_symbol *longer = a->len > b->len ? a : b;
+ const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
+ int d = longer->len - shorter->len;
+
+ out->missmatch = !memcmp(longer->line + d, shorter->line, shorter->len);
+ out->string = xmemdupz(longer->line, d);
+ out->direction = (a == longer);
+}
+
+static int compare_ws_delta(const struct ws_delta *a, const struct ws_delta *b)
+{
+ return a->direction == b->direction && !strcmp(a->string, b->string);
+}
+
static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
const void *entry,
const void *entry_or_key,
@@ -720,6 +745,15 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
unsigned flags = diffopt->color_moved_ws_handling
& XDF_WHITESPACE_FLAGS;
+ if (diffopt->color_moved_ws_handling & COLOR_MOVED_DELTA_WHITESPACES)
+ /*
+ * As there is not specific white space config given,
+ * we'd need to check for a new block, so ignore all
+ * white space. The setup of the white space
+ * configuration for the next block is done else where
+ */
+ flags |= XDF_IGNORE_WHITESPACE;
+
return !xdiff_compare_lines(a->es->line, a->es->len,
b->es->line, b->es->len,
flags);
@@ -772,7 +806,8 @@ static void add_lines_to_move_detection(struct diff_options *o,
}
static int shrink_potential_moved_blocks(struct moved_entry **pmb,
- int pmb_nr)
+ int pmb_nr,
+ struct ws_delta **wsd)
{
int lp, rp;
@@ -788,6 +823,10 @@ static int shrink_potential_moved_blocks(struct moved_entry **pmb,
if (lp < pmb_nr && rp > -1 && lp < rp) {
pmb[lp] = pmb[rp];
+ if (*wsd) {
+ free((*wsd)[lp].string);
+ (*wsd)[lp] = (*wsd)[rp];
+ }
pmb[rp] = NULL;
rp--;
lp++;
@@ -837,8 +876,11 @@ static void mark_color_as_moved(struct diff_options *o,
{
struct moved_entry **pmb = NULL; /* potentially moved blocks */
int pmb_nr = 0, pmb_alloc = 0;
- int n, flipped_block = 1, block_length = 0;
+ struct ws_delta *wsd = NULL; /* white space deltas between pmb */
+ int wsd_alloc = 0;
+
+ int n, flipped_block = 1, block_length = 0;
for (n = 0; n < o->emitted_symbols->nr; n++) {
struct hashmap *hm = NULL;
@@ -881,14 +923,31 @@ static void mark_color_as_moved(struct diff_options *o,
struct moved_entry *p = pmb[i];
struct moved_entry *pnext = (p && p->next_line) ?
p->next_line : NULL;
- if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
- pmb[i] = p->next_line;
+
+ if (o->color_moved_ws_handling & COLOR_MOVED_DELTA_WHITESPACES) {
+ struct ws_delta out = WS_DELTA_INIT;
+
+ if (pnext)
+ compute_ws_delta(l, pnext->es, &out);
+ if (pnext &&
+ !hm->cmpfn(o, pnext, match, NULL) &&
+ compare_ws_delta(&out, &wsd[i])) {
+ pmb[i] = p->next_line;
+ /* wsd[i] is the same */
+ } else {
+ pmb[i] = NULL;
+ }
+ free(out.string);
} else {
- pmb[i] = NULL;
+ if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
+ pmb[i] = p->next_line;
+ } else {
+ pmb[i] = NULL;
+ }
}
}
- pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
+ pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr, &wsd);
if (pmb_nr == 0) {
/*
@@ -897,6 +956,10 @@ static void mark_color_as_moved(struct diff_options *o,
*/
for (; match; match = hashmap_get_next(hm, match)) {
ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
+ if (o->color_moved_ws_handling & COLOR_MOVED_DELTA_WHITESPACES) {
+ ALLOC_GROW(wsd, pmb_nr + 1, wsd_alloc);
+ compute_ws_delta(l, match->es, &wsd[pmb_nr]);
+ }
pmb[pmb_nr++] = match;
}
@@ -914,6 +977,7 @@ static void mark_color_as_moved(struct diff_options *o,
adjust_last_block(o, n, block_length);
free(pmb);
+ free(wsd);
}
#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
@@ -4647,12 +4711,16 @@ int diff_opt_parse(struct diff_options *options,
options->color_moved_ws_handling &= ~XDF_IGNORE_WHITESPACE_CHANGE;
else if (!strcmp(arg, "--color-moved-no-ignore-space-at-eol"))
options->color_moved_ws_handling &= ~XDF_IGNORE_WHITESPACE_AT_EOL;
+ else if (!strcmp(arg, "--color-moved-no-ignore-space-prefix-delta"))
+ options->color_moved_ws_handling &= ~COLOR_MOVED_DELTA_WHITESPACES;
else if (!strcmp(arg, "--color-moved-ignore-all-space"))
options->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
else if (!strcmp(arg, "--color-moved-ignore-space-change"))
options->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE_CHANGE;
else if (!strcmp(arg, "--color-moved-ignore-space-at-eol"))
options->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE_AT_EOL;
+ else if (!strcmp(arg, "--color-moved-ignore-space-prefix-delta"))
+ options->color_moved_ws_handling |= COLOR_MOVED_DELTA_WHITESPACES;
else if (!strcmp(arg, "--indent-heuristic"))
DIFF_XDL_SET(options, INDENT_HEURISTIC);
else if (!strcmp(arg, "--no-indent-heuristic"))
@@ -5558,6 +5626,9 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
hashmap_init(&del_lines, moved_entry_cmp, o, 0);
hashmap_init(&add_lines, moved_entry_cmp, o, 0);
+ if (o->color_moved_ws_handling & COLOR_MOVED_DELTA_WHITESPACES)
+ o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
+
add_lines_to_move_detection(o, &add_lines, &del_lines);
mark_color_as_moved(o, &add_lines, &del_lines);
if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
diff --git a/diff.h b/diff.h
index de5dc68005..b00ea76c08 100644
--- a/diff.h
+++ b/diff.h
@@ -214,6 +214,8 @@ struct diff_options {
} color_moved;
#define COLOR_MOVED_DEFAULT COLOR_MOVED_ZEBRA
#define COLOR_MOVED_MIN_ALNUM_COUNT 20
+ /* XDF_WHITESPACE_FLAGS regarding block detection are set at 2, 3, 4 */
+ #define COLOR_MOVED_DELTA_WHITESPACES (1 << 22)
int color_moved_ws_handling;
};
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 751fc478dd..3e94cf051d 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1847,4 +1847,58 @@ test_expect_success 'only move detection ignores white spaces' '
test_cmp expected actual
'
+test_expect_success 'compare whitespace delta across moved blocks' '
+
+ git reset --hard &&
+ q_to_tab <<-\EOF >text.txt &&
+ QIndented
+ QText across
+ Qthree lines
+ QBut! <- this stands out
+ Qthis one
+ QQline did
+ Qnot adjust
+ EOF
+
+ git add text.txt &&
+ git commit -m "add text.txt" &&
+
+ q_to_tab <<-\EOF >text.txt &&
+ QQIndented
+ QQText across
+ QQthree lines
+ QQQBut! <- this stands out
+ this one
+ Qline did
+ not adjust
+ EOF
+
+ git diff --color --color-moved-ignore-space-prefix-delta |
+ grep -v "index" |
+ test_decode_color >actual &&
+
+ q_to_tab <<-\EOF >expected &&
+ <BOLD>diff --git a/text.txt b/text.txt<RESET>
+ <BOLD>--- a/text.txt<RESET>
+ <BOLD>+++ b/text.txt<RESET>
+ <CYAN>@@ -1,7 +1,7 @@<RESET>
+ <RED>-QIndented<RESET>
+ <RED>-QText across<RESET>
+ <RED>-Qthree lines<RESET>
+ <RED>-QBut! <- this stands out<RESET>
+ <RED>-Qthis one<RESET>
+ <RED>-QQline did<RESET>
+ <RED>-Qnot adjust<RESET>
+ <GREEN>+<RESET>QQ<GREEN>Indented<RESET>
+ <GREEN>+<RESET>QQ<GREEN>Text across<RESET>
+ <GREEN>+<RESET>QQ<GREEN>three lines<RESET>
+ <GREEN>+<RESET>QQQ<GREEN>But! <- this stands out<RESET>
+ <GREEN>+<RESET><GREEN>this one<RESET>
+ <GREEN>+<RESET>Q<GREEN>line did<RESET>
+ <GREEN>+<RESET><GREEN>not adjust<RESET>
+ EOF
+
+ test_cmp expected actual
+'
+
test_done
--
2.17.0.441.gb46fe60e1d-goog
Stefan Beller