Skip to content
Browse files

diff: add --ignore-blank-lines option

The goal of the patch is to introduce the GNU diff
-B/--ignore-blank-lines as closely as possible. The short option is not
available because it's already used for "break-rewrites".

When this option is used, git-diff will not create hunks that simply
add or remove empty lines, but will still show empty lines
addition/suppression if they are close enough to "valuable" changes.

There are two differences between this option and GNU diff -B option:
- GNU diff doesn't have "--inter-hunk-context", so this must be handled
- The following sequence looks like a bug (context is displayed twice):

    $ seq 5 >file1
    $ cat <<EOF >file2
    change
    1
    2

    3
    4
    5
    change
    EOF
    $ diff -u -B file1 file2
    --- file1	2013-06-08 22:13:04.471517834 +0200
    +++ file2	2013-06-08 22:13:23.275517855 +0200
    @@ -1,5 +1,7 @@
    +change
     1
     2
    +
     3
     4
     5
    @@ -3,3 +5,4 @@
     3
     4
     5
    +change

So here is a more thorough description of the option:
- real changes are interesting
- blank lines that are close enough (less than context size) to
interesting changes are considered interesting (recursive definition)
- "context" lines are used around each hunk of interesting changes
- If two hunks are separated by less than "inter-hunk-context", they
will be merged into one.

The implementation does the "interesting changes selection" in a single
pass.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
  • Loading branch information...
1 parent edca415 commit 36617af7ed594d1928554356d809bd611c642dd2 @apelisse apelisse committed with gitster
Showing with 439 additions and 8 deletions.
  1. +3 −0 Documentation/diff-options.txt
  2. +2 −0 diff.c
  3. +345 −0 t/t4015-diff-whitespace.sh
  4. +2 −0 xdiff/xdiff.h
  5. +28 −1 xdiff/xdiffi.c
  6. +1 −0 xdiff/xdiffi.h
  7. +43 −6 xdiff/xemit.c
  8. +1 −1 xdiff/xemit.h
  9. +13 −0 xdiff/xutils.c
  10. +1 −0 xdiff/xutils.h
View
3 Documentation/diff-options.txt
@@ -439,6 +439,9 @@ endif::git-format-patch[]
differences even if one line has whitespace where the other
line has none.
+--ignore-blank-lines::
+ Ignore changes whose lines are all blank.
+
--inter-hunk-context=<lines>::
Show the context between diff hunks, up to the specified number
of lines, thereby fusing hunks that are close to each other.
View
2 diff.c
@@ -3593,6 +3593,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
else if (!strcmp(arg, "--ignore-space-at-eol"))
DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
+ else if (!strcmp(arg, "--ignore-blank-lines"))
+ DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
else if (!strcmp(arg, "--patience"))
options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
else if (!strcmp(arg, "--histogram"))
View
345 t/t4015-diff-whitespace.sh
@@ -142,6 +142,351 @@ EOF
git diff --ignore-space-at-eol > out
test_expect_success 'another test, with --ignore-space-at-eol' 'test_cmp expect out'
+test_expect_success 'ignore-blank-lines: only new lines' '
+ test_seq 5 >x &&
+ git update-index x &&
+ test_seq 5 | sed "/3/i \\
+" >x &&
+ git diff --ignore-blank-lines >out &&
+ >expect &&
+ test_cmp out expect
+'
+
+test_expect_success 'ignore-blank-lines: only new lines with space' '
+ test_seq 5 >x &&
+ git update-index x &&
+ test_seq 5 | sed "/3/i \ " >x &&
+ git diff -w --ignore-blank-lines >out &&
+ >expect &&
+ test_cmp out expect
+'
+
+test_expect_success 'ignore-blank-lines: after change' '
+ cat <<-\EOF >x &&
+ 1
+ 2
+
+ 3
+ 4
+ 5
+
+ 6
+ 7
+ EOF
+ git update-index x &&
+ cat <<-\EOF >x &&
+ change
+
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+
+ 7
+ EOF
+ git diff --inter-hunk-context=100 --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -1,6 +1,7 @@
+ +change
+ +
+ 1
+ 2
+ -
+ 3
+ 4
+ 5
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
+test_expect_success 'ignore-blank-lines: before change' '
+ cat <<-\EOF >x &&
+ 1
+ 2
+
+ 3
+ 4
+ 5
+ 6
+ 7
+ EOF
+ git update-index x &&
+ cat <<-\EOF >x &&
+
+ 1
+ 2
+ 3
+ 4
+ 5
+
+ 6
+ 7
+ change
+ EOF
+ git diff --inter-hunk-context=100 --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -4,5 +4,7 @@
+ 3
+ 4
+ 5
+ +
+ 6
+ 7
+ +change
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
+test_expect_success 'ignore-blank-lines: between changes' '
+ cat <<-\EOF >x &&
+ 1
+ 2
+ 3
+ 4
+ 5
+
+
+ 6
+ 7
+ 8
+ 9
+ 10
+ EOF
+ git update-index x &&
+ cat <<-\EOF >x &&
+ change
+ 1
+ 2
+
+ 3
+ 4
+ 5
+ 6
+ 7
+ 8
+
+ 9
+ 10
+ change
+ EOF
+ git diff --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -1,5 +1,7 @@
+ +change
+ 1
+ 2
+ +
+ 3
+ 4
+ 5
+ @@ -8,5 +8,7 @@
+ 6
+ 7
+ 8
+ +
+ 9
+ 10
+ +change
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
+test_expect_success 'ignore-blank-lines: between changes (with interhunkctx)' '
+ test_seq 10 >x &&
+ git update-index x &&
+ cat <<-\EOF >x &&
+ change
+ 1
+ 2
+
+ 3
+ 4
+ 5
+
+ 6
+ 7
+ 8
+ 9
+
+ 10
+ change
+ EOF
+ git diff --inter-hunk-context=2 --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -1,10 +1,15 @@
+ +change
+ 1
+ 2
+ +
+ 3
+ 4
+ 5
+ +
+ 6
+ 7
+ 8
+ 9
+ +
+ 10
+ +change
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
+test_expect_success 'ignore-blank-lines: scattered spaces' '
+ test_seq 10 >x &&
+ git update-index x &&
+ cat <<-\EOF >x &&
+ change
+ 1
+ 2
+ 3
+
+ 4
+
+ 5
+
+ 6
+
+
+ 7
+
+ 8
+ 9
+ 10
+ change
+ EOF
+ git diff --inter-hunk-context=4 --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -1,3 +1,4 @@
+ +change
+ 1
+ 2
+ 3
+ @@ -8,3 +15,4 @@
+ 8
+ 9
+ 10
+ +change
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
+test_expect_success 'ignore-blank-lines: spaces coalesce' '
+ test_seq 6 >x &&
+ git update-index x &&
+ cat <<-\EOF >x &&
+ change
+ 1
+ 2
+ 3
+
+ 4
+
+ 5
+
+ 6
+ change
+ EOF
+ git diff --inter-hunk-context=4 --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -1,6 +1,11 @@
+ +change
+ 1
+ 2
+ 3
+ +
+ 4
+ +
+ 5
+ +
+ 6
+ +change
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
+test_expect_success 'ignore-blank-lines: mix changes and blank lines' '
+ test_seq 16 >x &&
+ git update-index x &&
+ cat <<-\EOF >x &&
+ change
+ 1
+ 2
+
+ 3
+ 4
+ 5
+ change
+ 6
+ 7
+ 8
+
+ 9
+ 10
+ 11
+ change
+ 12
+ 13
+ 14
+
+ 15
+ 16
+ change
+ EOF
+ git diff --ignore-blank-lines >out.tmp &&
+ cat <<-\EOF >expected &&
+ diff --git a/x b/x
+ --- a/x
+ +++ b/x
+ @@ -1,8 +1,11 @@
+ +change
+ 1
+ 2
+ +
+ 3
+ 4
+ 5
+ +change
+ 6
+ 7
+ 8
+ @@ -9,8 +13,11 @@
+ 9
+ 10
+ 11
+ +change
+ 12
+ 13
+ 14
+ +
+ 15
+ 16
+ +change
+ EOF
+ compare_diff_patch expected out.tmp
+'
+
test_expect_success 'check mixed spaces and tabs in indent' '
# This is indented with SP HT SP.
View
2 xdiff/xdiff.h
@@ -39,6 +39,8 @@ extern "C" {
#define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF)
#define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK)
+#define XDF_IGNORE_BLANK_LINES (1 << 7)
+
#define XDL_EMIT_FUNCNAMES (1 << 0)
#define XDL_EMIT_COMMON (1 << 1)
#define XDL_EMIT_FUNCCONTEXT (1 << 2)
View
29 xdiff/xdiffi.c
@@ -394,6 +394,7 @@ static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1,
xch->i2 = i2;
xch->chg1 = chg1;
xch->chg2 = chg2;
+ xch->ignore = 0;
return xch;
}
@@ -544,7 +545,9 @@ static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
xdchange_t *xch, *xche;
for (xch = xscr; xch; xch = xche->next) {
- xche = xdl_get_hunk(xch, xecfg);
+ xche = xdl_get_hunk(&xch, xecfg);
+ if (!xch)
+ break;
if (xecfg->hunk_func(xch->i1, xche->i1 + xche->chg1 - xch->i1,
xch->i2, xche->i2 + xche->chg2 - xch->i2,
ecb->priv) < 0)
@@ -553,6 +556,27 @@ static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
return 0;
}
+static void xdl_mark_ignorable(xdchange_t *xscr, xdfenv_t *xe, long flags)
+{
+ xdchange_t *xch;
+
+ for (xch = xscr; xch; xch = xch->next) {
+ int ignore = 1;
+ xrecord_t **rec;
+ long i;
+
+ rec = &xe->xdf1.recs[xch->i1];
+ for (i = 0; i < xch->chg1 && ignore; i++)
+ ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+
+ rec = &xe->xdf2.recs[xch->i2];
+ for (i = 0; i < xch->chg2 && ignore; i++)
+ ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+
+ xch->ignore = ignore;
+ }
+}
+
int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
xdemitconf_t const *xecfg, xdemitcb_t *ecb) {
xdchange_t *xscr;
@@ -571,6 +595,9 @@ int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
return -1;
}
if (xscr) {
+ if (xpp->flags & XDF_IGNORE_BLANK_LINES)
+ xdl_mark_ignorable(xscr, &xe, xpp->flags);
+
if (ef(&xe, xscr, ecb, xecfg) < 0) {
xdl_free_script(xscr);
View
1 xdiff/xdiffi.h
@@ -41,6 +41,7 @@ typedef struct s_xdchange {
struct s_xdchange *next;
long i1, i2;
long chg1, chg2;
+ int ignore;
} xdchange_t;
View
49 xdiff/xemit.c
@@ -56,16 +56,51 @@ static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *
/*
* Starting at the passed change atom, find the latest change atom to be included
* inside the differential hunk according to the specified configuration.
+ * Also advance xscr if the first changes must be discarded.
*/
-xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
- xdchange_t *xch, *xchp;
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
+{
+ xdchange_t *xch, *xchp, *lxch;
long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
+ long max_ignorable = xecfg->ctxlen;
+ unsigned long ignored = 0; /* number of ignored blank lines */
+
+ /* remove ignorable changes that are too far before other changes */
+ for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
+ xch = xchp->next;
+
+ if (xch == NULL ||
+ xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable)
+ *xscr = xch;
+ }
+
+ if (*xscr == NULL)
+ return NULL;
+
+ lxch = *xscr;
- for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
- if (xch->i1 - (xchp->i1 + xchp->chg1) > max_common)
+ for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) {
+ long distance = xch->i1 - (xchp->i1 + xchp->chg1);
+ if (distance > max_common)
break;
- return xchp;
+ if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) {
+ lxch = xch;
+ ignored = 0;
+ } else if (distance < max_ignorable && xch->ignore) {
+ ignored += xch->chg2;
+ } else if (lxch != xchp &&
+ xch->i1 + ignored - (lxch->i1 + lxch->chg1) > max_common) {
+ break;
+ } else if (!xch->ignore) {
+ lxch = xch;
+ ignored = 0;
+ } else {
+ ignored += xch->chg2;
+ }
+ }
+
+ return lxch;
}
@@ -139,7 +174,9 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
return xdl_emit_common(xe, xscr, ecb, xecfg);
for (xch = xscr; xch; xch = xche->next) {
- xche = xdl_get_hunk(xch, xecfg);
+ xche = xdl_get_hunk(&xch, xecfg);
+ if (!xch)
+ break;
s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
View
2 xdiff/xemit.h
@@ -27,7 +27,7 @@
typedef int (*emit_func_t)(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
xdemitconf_t const *xecfg);
-xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg);
int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
xdemitconf_t const *xecfg);
View
13 xdiff/xutils.c
@@ -143,6 +143,19 @@ long xdl_guess_lines(mmfile_t *mf, long sample) {
return nl + 1;
}
+int xdl_blankline(const char *line, long size, long flags)
+{
+ long i;
+
+ if (!(flags & XDF_WHITESPACE_FLAGS))
+ return (size <= 1);
+
+ for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
+ ;
+
+ return (i == size);
+}
+
int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
{
int i1, i2;
View
1 xdiff/xutils.h
@@ -32,6 +32,7 @@ int xdl_cha_init(chastore_t *cha, long isize, long icount);
void xdl_cha_free(chastore_t *cha);
void *xdl_cha_alloc(chastore_t *cha);
long xdl_guess_lines(mmfile_t *mf, long sample);
+int xdl_blankline(const char *line, long size, long flags);
int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags);
unsigned long xdl_hash_record(char const **data, char const *top, long flags);
unsigned int xdl_hashbits(unsigned int size);

0 comments on commit 36617af

Please sign in to comment.
Something went wrong with that request. Please try again.