Re: git log -S or -G

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> I think that is the best we could do for "-S", though, which is
> inherently about counting hits.
>
> For "-G", we are literally grepping the diff. It does not seem
> unreasonable to add the ability to grep only "-" or "+" lines, and the
> interface for that should be pretty straightforward (a tri-state flag to
> look in remove, added, or both lines).

Yeah, here is a lunchtime hack that hasn't even been compile tested.

 diff.c             |  4 ++++
 diff.h             |  2 ++
 diffcore-pickaxe.c | 22 ++++++++++++++++++++--
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/diff.c b/diff.c
index f0c7557b40..d1f2780844 100644
--- a/diff.c
+++ b/diff.c
@@ -5068,6 +5068,10 @@ int diff_opt_parse(struct diff_options *options,
 	}
 	else if (!strcmp(arg, "--pickaxe-all"))
 		options->pickaxe_opts |= DIFF_PICKAXE_ALL;
+	else if (!strcmp(arg, "--pickaxe-ignore-add"))
+		options->pickaxe_opts |= DIFF_PICKAXE_IGNORE_ADD;
+	else if (!strcmp(arg, "--pickaxe-ignore-del"))
+		options->pickaxe_opts |= DIFF_PICKAXE_IGNORE_DEL;
 	else if (!strcmp(arg, "--pickaxe-regex"))
 		options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 	else if ((argcount = short_opt('O', av, &optarg))) {
diff --git a/diff.h b/diff.h
index a30cc35ec3..147c47ace7 100644
--- a/diff.h
+++ b/diff.h
@@ -358,6 +358,8 @@ int git_config_rename(const char *var, const char *value);
 				 DIFF_PICKAXE_KIND_OBJFIND)
 
 #define DIFF_PICKAXE_IGNORE_CASE	32
+#define DIFF_PICKAXE_IGNORE_ADD	64
+#define DIFF_PICKAXE_IGNORE_DEL 128
 
 void diffcore_std(struct diff_options *);
 void diffcore_fix_diff_index(struct diff_options *);
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index 800a899c86..826dde6bd4 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -16,6 +16,7 @@ typedef int (*pickaxe_fn)(mmfile_t *one, mmfile_t *two,
 
 struct diffgrep_cb {
 	regex_t *regexp;
+	struct diff_options *diff_options;
 	int hit;
 };
 
@@ -23,9 +24,14 @@ static void diffgrep_consume(void *priv, char *line, unsigned long len)
 {
 	struct diffgrep_cb *data = priv;
 	regmatch_t regmatch;
+	unsigned pickaxe_opts = data->diff_options->pickaxe_opts;
 
 	if (line[0] != '+' && line[0] != '-')
 		return;
+	if ((pickaxe_opts & DIFF_PICKAXE_IGNORE_ADD) &&	line[0] == '+')
+		return;
+	if ((pickaxe_opts & DIFF_PICKAXE_IGNORE_DEL) &&	line[0] == '-')
+		return;
 	if (data->hit)
 		/*
 		 * NEEDSWORK: we should have a way to terminate the
@@ -45,13 +51,20 @@ static int diff_grep(mmfile_t *one, mmfile_t *two,
 	xpparam_t xpp;
 	xdemitconf_t xecfg;
 
-	if (!one)
+	if (!one) {
+		if (o->pickaxe_opts & DIFF_PICKAXE_IGNORE_ADD)
+			return 0;
 		return !regexec_buf(regexp, two->ptr, two->size,
 				    1, &regmatch, 0);
-	if (!two)
+	}
+	if (!two) {
+		if (o->pickaxe_opts & DIFF_PICKAXE_IGNORE_DEL)
+			return 0;
 		return !regexec_buf(regexp, one->ptr, one->size,
 				    1, &regmatch, 0);
+	}
 
+	ecbdata.diff_options = o;
 	/*
 	 * We have both sides; need to run textual diff and see if
 	 * the pattern appears on added/deleted lines.
@@ -113,6 +126,11 @@ static int has_changes(mmfile_t *one, mmfile_t *two,
 {
 	unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
 	unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
+
+	if (o->pickaxe_opts & DIFF_PICKAXE_IGNORE_ADD)
+		return one_contains > two_contains;
+	if (o->pickaxe_opts & DIFF_PICKAXE_IGNORE_DEL)
+		return one_contains < two_contains;
 	return one_contains != two_contains;
 }