Merge branch 'js/apply-recount'

* js/apply-recount:
  Allow git-apply to recount the lines in a hunk (AKA recountdiff)

3 files changed, 101 insertions, 43 deletions

diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
index c8347637d..c5ee636fa 100644
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -12,7 +12,7 @@ SYNOPSIS
 'git-apply' [--stat] [--numstat] [--summary] [--check] [--index]
 	  [--apply] [--no-add] [--build-fake-ancestor <file>] [-R | --reverse]
 	  [--allow-binary-replacement | --binary] [--reject] [-z]
-	  [-pNUM] [-CNUM] [--inaccurate-eof] [--cached]
+	  [-pNUM] [-CNUM] [--inaccurate-eof] [--recount] [--cached]
 	  [--whitespace=<nowarn|warn|fix|error|error-all>]
 	  [--exclude=PATH] [--verbose] [<patch>...]
 
@@ -177,6 +177,11 @@ behavior:
 	current patch being applied will be printed. This option will cause
 	additional information to be reported.
 
+--recount::
+	Do not trust the line counts in the hunk headers, but infer them
+	by inspecting the patch (e.g. after editing the patch without
+	adjusting the hunk headers appropriately).
+
 Configuration
 -------------
 
diff --git a/builtin-apply.c b/builtin-apply.c
index 985ca3be5..9fcfe3955 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -154,6 +154,7 @@ struct patch {
 	unsigned int is_binary:1;
 	unsigned int is_copy:1;
 	unsigned int is_rename:1;
+	unsigned int recount:1;
 	struct fragment *fragments;
 	char *result;
 	size_t resultsize;
@@ -890,6 +891,56 @@ static int parse_range(const char *line, int len, int offset, const char *expect
 	return offset + ex;
 }
 
+static void recount_diff(char *line, int size, struct fragment *fragment)
+{
+	int oldlines = 0, newlines = 0, ret = 0;
+
+	if (size < 1) {
+		warning("recount: ignore empty hunk");
+		return;
+	}
+
+	for (;;) {
+		int len = linelen(line, size);
+		size -= len;
+		line += len;
+
+		if (size < 1)
+			break;
+
+		switch (*line) {
+		case ' ': case '\n':
+			newlines++;
+			/* fall through */
+		case '-':
+			oldlines++;
+			continue;
+		case '+':
+			newlines++;
+			continue;
+		case '\\':
+			break;
+		case '@':
+			ret = size < 3 || prefixcmp(line, "@@ ");
+			break;
+		case 'd':
+			ret = size < 5 || prefixcmp(line, "diff ");
+			break;
+		default:
+			ret = -1;
+			break;
+		}
+		if (ret) {
+			warning("recount: unexpected line: %.*s",
+				(int)linelen(line, size), line);
+			return;
+		}
+		break;
+	}
+	fragment->oldlines = oldlines;
+	fragment->newlines = newlines;
+}
+
 /*
  * Parse a unified diff fragment header of the
  * form "@@ -a,b +c,d @@"
@@ -1020,6 +1071,8 @@ static int parse_fragment(char *line, unsigned long size,
 	offset = parse_fragment_header(line, len, fragment);
 	if (offset < 0)
 		return -1;
+	if (offset > 0 && patch->recount)
+		recount_diff(line + offset, size - offset, fragment);
 	oldlines = fragment->oldlines;
 	newlines = fragment->newlines;
 	leading = 0;
@@ -2971,7 +3024,10 @@ static void prefix_patches(struct patch *p)
 	}
 }
 
-static int apply_patch(int fd, const char *filename, int inaccurate_eof)
+#define INACCURATE_EOF	(1<<0)
+#define RECOUNT		(1<<1)
+
+static int apply_patch(int fd, const char *filename, int options)
 {
 	size_t offset;
 	struct strbuf buf;
@@ -2989,7 +3045,8 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
 		int nr;
 
 		patch = xcalloc(1, sizeof(*patch));
-		patch->inaccurate_eof = inaccurate_eof;
+		patch->inaccurate_eof = !!(options & INACCURATE_EOF);
+		patch->recount =  !!(options & RECOUNT);
 		nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
 		if (nr < 0)
 			break;
@@ -3058,7 +3115,7 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 {
 	int i;
 	int read_stdin = 1;
-	int inaccurate_eof = 0;
+	int options = 0;
 	int errs = 0;
 	int is_not_gitdir;
 
@@ -3076,7 +3133,7 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 		int fd;
 
 		if (!strcmp(arg, "-")) {
-			errs |= apply_patch(0, "<stdin>", inaccurate_eof);
+			errs |= apply_patch(0, "<stdin>", options);
 			read_stdin = 0;
 			continue;
 		}
@@ -3176,7 +3233,11 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 			continue;
 		}
 		if (!strcmp(arg, "--inaccurate-eof")) {
-			inaccurate_eof = 1;
+			options |= INACCURATE_EOF;
+			continue;
+		}
+		if (!strcmp(arg, "--recount")) {
+			options |= RECOUNT;
 			continue;
 		}
 		if (0 < prefix_length)
@@ -3187,12 +3248,12 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 			die("can't open patch '%s': %s", arg, strerror(errno));
 		read_stdin = 0;
 		set_default_whitespace_mode(whitespace_option);
-		errs |= apply_patch(fd, arg, inaccurate_eof);
+		errs |= apply_patch(fd, arg, options);
 		close(fd);
 	}
 	set_default_whitespace_mode(whitespace_option);
 	if (read_stdin)
-		errs |= apply_patch(0, "<stdin>", inaccurate_eof);
+		errs |= apply_patch(0, "<stdin>", options);
 	if (whitespace_error) {
 		if (squelch_whitespace_errors &&
 		    squelch_whitespace_errors < whitespace_error) {
diff --git a/t/t4100-apply-stat.sh b/t/t4100-apply-stat.sh
index 8073a5a1f..be837bb98 100755
--- a/t/t4100-apply-stat.sh
+++ b/t/t4100-apply-stat.sh
@@ -3,44 +3,36 @@
 # Copyright (c) 2005 Junio C Hamano
 #
 
-test_description='git apply --stat --summary test.
+test_description='git apply --stat --summary test, with --recount
 
 '
 . ./test-lib.sh
 
-test_expect_success \
-    'rename' \
-    'git apply --stat --summary <../t4100/t-apply-1.patch >current &&
-    test_cmp ../t4100/t-apply-1.expect current'
-
-test_expect_success \
-    'copy' \
-    'git apply --stat --summary <../t4100/t-apply-2.patch >current &&
-    test_cmp ../t4100/t-apply-2.expect current'
-
-test_expect_success \
-    'rewrite' \
-    'git apply --stat --summary <../t4100/t-apply-3.patch >current &&
-    test_cmp ../t4100/t-apply-3.expect current'
-
-test_expect_success \
-    'mode' \
-    'git apply --stat --summary <../t4100/t-apply-4.patch >current &&
-    test_cmp ../t4100/t-apply-4.expect current'
-
-test_expect_success \
-    'non git' \
-    'git apply --stat --summary <../t4100/t-apply-5.patch >current &&
-    test_cmp ../t4100/t-apply-5.expect current'
-
-test_expect_success \
-    'non git' \
-    'git apply --stat --summary <../t4100/t-apply-6.patch >current &&
-    test_cmp ../t4100/t-apply-6.expect current'
-
-test_expect_success \
-    'non git' \
-    'git apply --stat --summary <../t4100/t-apply-7.patch >current &&
-    test_cmp ../t4100/t-apply-7.expect current'
+UNC='s/^\(@@ -[1-9][0-9]*\),[0-9]* \(+[1-9][0-9]*\),[0-9]* @@/\1,999 \2,999 @@/'
+
+num=0
+while read title
+do
+	num=$(( $num + 1 ))
+	test_expect_success "$title" '
+		git apply --stat --summary \
+			<"$TEST_DIRECTORY/t4100/t-apply-$num.patch" >current &&
+		test_cmp ../t4100/t-apply-$num.expect current
+	'
+
+	test_expect_success "$title with recount" '
+		sed -e "$UNC" <"$TEST_DIRECTORY/t4100/t-apply-$num.patch" |
+		git apply --recount --stat --summary >current &&
+		test_cmp ../t4100/t-apply-$num.expect current
+	'
+done <<\EOF
+rename
+copy
+rewrite
+mode
+non git (1)
+non git (2)
+non git (3)
+EOF
 
 test_done