Re: [PATCH] git-add--interactive: manual hunk editing mode

@@ -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] [--fixup] [--cached]
 	  [--whitespace=<nowarn|warn|fix|error|error-all>]
 	  [--exclude=PATH] [--verbose] [<patch>...]
 

@@ -169,6 +169,10 @@ behavior:
 	correctly. This option adds support for applying such patches by
 	working around this bug.
 
+--fixup-line-counts::
+	Fix up the line counts (e.g. after editing the patch without
+	adjusting the hunk headers appropriately).
+
 -v, --verbose::
 	Report progress to stderr. By default, only a message about the
 	current patch being applied will be printed. This option will cause

@@ -153,6 +153,7 @@ struct patch {
 	unsigned int is_binary:1;
 	unsigned int is_copy:1;
 	unsigned int is_rename:1;
+	unsigned int fixup:1;
 	struct fragment *fragments;
 	char *result;
 	size_t resultsize;

@@ -882,11 +883,49 @@ static int parse_range(const char *line, int len, int offset, const char *expect
 	return offset + ex;
 }
 
+static int fixup_counts(char *line, int len, struct fragment *fragment)
+{
+
+	if (len < 1)
+		return -1;
+
+	fragment->oldlines = fragment->newlines = 0;
+
+	for (;;) {
+		char *newline = memchr(line, '\n', len);
+		if (!newline)
+			break;
+
+		switch (*line) {
+		case ' ':
+			fragment->oldlines++;
+			/* fall through */
+		case '+':
+			fragment->newlines++;
+			break;
+		case '-':
+			fragment->oldlines++;
+			break;
+		default:
+			return error("Unexpected first character: %c in line "
+				"'%.*s'",
+				*line, newline ? newline - line : len, line);
+		}
+
+		len -= newline + 1 - line;
+		line = newline + 1;
+		if (len < 2 || !prefixcmp(line, "@@"))
+			break;
+	}
+	return 0;
+}
+
 /*
  * Parse a unified diff fragment header of the
  * form "@@ -a,b +c,d @@"
  */
-static int parse_fragment_header(char *line, int len, struct fragment *fragment)
+static int parse_fragment_header(char *line, int len, struct fragment *fragment,
+	int fixup)
 {
 	int offset;
 

@@ -897,6 +936,10 @@ static int parse_fragment_header(char *line, int len, struct fragment *fragment)
 	offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
 	offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
 
+	if (offset > 0 && fixup &&
+			fixup_counts(line + offset, len - offset, fragment))
+		return -1;
+
 	return offset;
 }
 

@@ -927,7 +970,8 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
 		 */
 		if (!memcmp("@@ -", line, 4)) {
 			struct fragment dummy;
-			if (parse_fragment_header(line, len, &dummy) < 0)
+			if (parse_fragment_header(line, len, &dummy,
+					patch->fixup) < 0)
 				continue;
 			die("patch fragment without header at line %d: %.*s",
 			    linenr, (int)len-1, line);

@@ -1010,7 +1054,7 @@ static int parse_fragment(char *line, unsigned long size,
 	unsigned long oldlines, newlines;
 	unsigned long leading, trailing;
 
-	offset = parse_fragment_header(line, len, fragment);
+	offset = parse_fragment_header(line, len, fragment, patch->fixup);
 	if (offset < 0)
 		return -1;
 	oldlines = fragment->oldlines;

@@ -2912,7 +2956,8 @@ static void prefix_patches(struct patch *p)
 	}
 }
 
-static int apply_patch(int fd, const char *filename, int inaccurate_eof)
+static int apply_patch(int fd, const char *filename, int inaccurate_eof,
+		int fixup)
 {
 	size_t offset;
 	struct strbuf buf;

@@ -2929,6 +2974,7 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
 
 		patch = xcalloc(1, sizeof(*patch));
 		patch->inaccurate_eof = inaccurate_eof;
+		patch->fixup = fixup;
 		nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
 		if (nr < 0)
 			break;

@@ -2998,6 +3044,7 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 	int i;
 	int read_stdin = 1;
 	int inaccurate_eof = 0;
+	int fixup = 0;
 	int errs = 0;
 	int is_not_gitdir;
 

@@ -3015,7 +3062,8 @@ 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>", inaccurate_eof,
+					fixup);
 			read_stdin = 0;
 			continue;
 		}

@@ -3118,6 +3166,10 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 			inaccurate_eof = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--fixup-line-counts")) {
+			fixup = 1;
+			continue;
+		}
 		if (0 < prefix_length)
 			arg = prefix_filename(prefix, prefix_length, arg);
 

@@ -3126,12 +3178,12 @@ 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, inaccurate_eof, fixup);
 		close(fd);
 	}
 	set_default_whitespace_mode(whitespace_option);
 	if (read_stdin)
-		errs |= apply_patch(0, "<stdin>", inaccurate_eof);
+		errs |= apply_patch(0, "<stdin>", inaccurate_eof, fixup);
 	if (whitespace_error) {
 		if (squelch_whitespace_errors &&
 		    squelch_whitespace_errors < whitespace_error) {