Re: [PATCH v2 1/2] Allow git-apply to ignore the hunk headers

@@ -8,8 +8,8 @@ git-add - Add file contents to the index
 SYNOPSIS
 --------
 [verse]
-'git-add' [-n] [-v] [-f] [--interactive | -i] [--patch | -p] [-u] [--refresh]
-	  [--ignore-errors] [--] <filepattern>...
+'git-add' [-n] [-v] [-f] [--interactive | -i] [--patch | -p] [--edit | -e]
+	  [-u] [--refresh] [--ignore-errors] [--] <filepattern>...
 
 DESCRIPTION
 -----------

@@ -70,6 +70,15 @@ OPTIONS
 	bypassed and the 'patch' subcommand is invoked using each of
 	the specified filepatterns before exiting.
 
+-e, \--edit::
+	Open the diff vs. the index in an editor and let the user
+	edit it.  After the editor was closed, adjust the hunk headers
+	and apply the patch to the index.
++
+*NOTE*: Obviously, if you change anything else than the first character
+on lines beginning with a space or a minus, the patch will no longer
+apply.
+
 -u::
 	Update only files that git already knows about, staging modified
 	content for commit and marking deleted files for removal. This

@@ -19,7 +19,7 @@ static const char * const builtin_add_usage[] = {
 	"git-add [options] [--] <filepattern>...",
 	NULL
 };
-static int patch_interactive = 0, add_interactive = 0;
+static int patch_interactive = 0, add_interactive = 0, edit_interactive = 0;
 static int take_worktree_changes;
 
 static void prune_directory(struct dir_struct *dir, const char **pathspec, int prefix)

@@ -186,6 +186,56 @@ int interactive_add(int argc, const char **argv, const char *prefix)
 	return status;
 }
 
+int edit_patch(int argc, const char **argv, const char *prefix)
+{
+	char *file = xstrdup(git_path("ADD_EDIT.patch"));
+	const char *apply_argv[] = { "apply", "--recount", "--cached",
+		file, NULL };
+	struct child_process child;
+	int result = 0, ac;
+	struct stat st;
+
+	memset(&child, 0, sizeof(child));
+	child.argv = xcalloc(sizeof(const char *), (argc + 5));
+	ac = 0;
+	child.git_cmd = 1;
+	child.argv[ac++] = "diff-files";
+	child.argv[ac++] = "--no-color";
+	child.argv[ac++] = "-p";
+	child.argv[ac++] = "--";
+	if (argc) {
+		const char **pathspec = validate_pathspec(argc, argv, prefix);
+		if (!pathspec)
+			return -1;
+		memcpy(&(child.argv[ac]), pathspec, sizeof(*argv) * argc);
+		ac += argc;
+	}
+	child.argv[ac] = NULL;
+	child.out = open(file, O_CREAT | O_WRONLY, 0644);
+	result = child.out < 0 && error("Could not write to '%s'", file);
+
+	if (!result)
+		result = run_command(&child);
+	free(child.argv);
+
+	launch_editor(file, NULL, NULL);
+
+	if (!result)
+		result = stat(file, &st) && error("Could not stat '%s'", file);
+	if (!result && !st.st_size)
+		result = error("Empty patch. Aborted.");
+
+	memset(&child, 0, sizeof(child));
+	child.git_cmd = 1;
+	child.argv = apply_argv;
+	if (!result)
+		result = run_command(&child) &&
+			error("Could not apply '%s'", file);
+	if (!result)
+		unlink(file);
+	return result;
+}
+
 static struct lock_file lock_file;
 
 static const char ignore_error[] =

@@ -200,6 +250,7 @@ static struct option builtin_add_options[] = {
 	OPT_GROUP(""),
 	OPT_BOOLEAN('i', "interactive", &add_interactive, "interactive picking"),
 	OPT_BOOLEAN('p', "patch", &patch_interactive, "interactive patching"),
+	OPT_BOOLEAN('e', "edit", &edit_interactive, "super-interactive patching"),
 	OPT_BOOLEAN('f', NULL, &ignored_too, "allow adding otherwise ignored files"),
 	OPT_BOOLEAN('u', NULL, &take_worktree_changes, "update tracked files"),
 	OPT_BOOLEAN( 0 , "refresh", &refresh_only, "don't add, only refresh the index"),

@@ -226,6 +277,8 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 
 	argc = parse_options(argc, argv, builtin_add_options,
 			  builtin_add_usage, 0);
+	if (edit_interactive)
+		return(edit_patch(argc, argv, prefix));
 	if (patch_interactive)
 		add_interactive = 1;
 	if (add_interactive)

@@ -0,0 +1,126 @@
+#!/bin/sh
+#
+# Copyright (c) 2007 Johannes E. Schindelin
+#
+
+test_description='add -e basic tests'
+. ./test-lib.sh
+
+
+cat > file << EOF
+LO, praise of the prowess of people-kings
+of spear-armed Danes, in days long sped,
+we have heard, and what honor the athelings won!
+Oft Scyld the Scefing from squadroned foes,
+from many a tribe, the mead-bench tore,
+awing the earls. Since erst he lay
+friendless, a foundling, fate repaid him:
+for he waxed under welkin, in wealth he throve,
+till before him the folk, both far and near,
+who house by the whale-path, heard his mandate,
+gave him gifts:  a good king he!
+EOF
+
+test_expect_success 'setup' '
+
+	git add file &&
+	test_tick &&
+	git commit -m initial file
+
+'
+
+cat > patch << EOF
+diff --git a/file b/file
+index b9834b5..ef6e94c 100644
+--- a/file
++++ b/file
+@@ -3,1 +3,333 @@ of spear-armed Danes, in days long sped,
+ we have heard, and what honor the athelings won!
++
+ Oft Scyld the Scefing from squadroned foes,
+@@ -2,7 +1,5 @@ awing the earls. Since erst he lay
+ friendless, a foundling, fate repaid him:
++
+ for he waxed under welkin, in wealth he throve,
+EOF
+
+cat > expected << EOF
+diff --git a/file b/file
+index b9834b5..ef6e94c 100644
+--- a/file
++++ b/file
+@@ -1,10 +1,12 @@
+ LO, praise of the prowess of people-kings
+ of spear-armed Danes, in days long sped,
+ we have heard, and what honor the athelings won!
++
+ Oft Scyld the Scefing from squadroned foes,
+ from many a tribe, the mead-bench tore,
+ awing the earls. Since erst he lay
+ friendless, a foundling, fate repaid him:
++
+ for he waxed under welkin, in wealth he throve,
+ till before him the folk, both far and near,
+ who house by the whale-path, heard his mandate,
+EOF
+
+echo "#!$SHELL_PATH" >fake-editor.sh
+cat >> fake-editor.sh <<\EOF
+mv -f "$1" orig-patch &&
+mv -f patch "$1"
+EOF
+
+test_set_editor "$(pwd)/fake-editor.sh"
+chmod a+x fake-editor.sh
+
+test_expect_success 'add -e' '
+
+	cp fake-editor.sh file &&
+	git add -e &&
+	test_cmp fake-editor.sh file &&
+	git diff --cached > out &&
+	test_cmp out expected
+
+'
+
+cat > patch << EOF
+diff --git a/file b/file
+--- a/file
++++ b/file
+@@ -1,1 +1,1 @@
+ gave him gifts:  a good king he!
++
+EOF
+
+test_expect_success 'add -e adds to the end of the file' '
+
+	test_tick &&
+	git commit -m update &&
+	git checkout &&
+	git add -e &&
+	git diff --cached > out &&
+	test "" = "$(git show :file | tail -n 1)"
+
+'
+
+cat > patch << EOF
+diff --git a/file b/file
+--- a/file
++++ b/file
+@@ -1,1 +1,1 @@
++
+ LO, praise of the prowess of people-kings
+EOF
+
+test_expect_success 'add -e adds to the beginning of the file' '
+
+	test_tick &&
+	git commit -m update &&
+	git checkout &&
+	git add -e &&
+	git diff --cached > out &&
+	test "" = "$(git show :file | head -n 1)"
+
+'
+
+test_done

@@ -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>...]
 

@@ -169,6 +169,11 @@ behavior:
 	correctly. This option adds support for applying such patches by
 	working around this bug.
 
+--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).
+
 -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 recount:1;
 	struct fragment *fragments;
 	char *result;
 	size_t resultsize;

@@ -882,6 +883,50 @@ static int parse_range(const char *line, int len, int offset, const char *expect
 	return offset + ex;
 }
 
+static int recount_diff(char *line, int size, struct fragment *fragment)
+{
+	int line_nr = 0;
+
+	if (size < 1)
+		return -1;
+
+	fragment->oldpos = 2;
+	fragment->oldlines = fragment->newlines = 0;
+
+	for (;;) {
+		int len = linelen(line, size);
+		size -= len;
+		line += len;
+
+		if (size < 1)
+			return 0;
+
+		switch (*line) {
+		case ' ': case '\n':
+			fragment->newlines++;
+			/* fall through */
+		case '-':
+			fragment->oldlines++;
+			break;
+		case '+':
+			fragment->newlines++;
+			if (line_nr == 0) {
+				fragment->leading = 1;
+				fragment->oldpos = 1;
+			}
+			fragment->trailing = 1;
+			break;
+		case '@':
+			return size < 3 || prefixcmp(line, "@@ ");
+		case 'd':
+			return size < 5 || prefixcmp(line, "diff ");
+		default:
+			return -1;
+		}
+		line_nr++;
+	}
+}
+
 /*
  * Parse a unified diff fragment header of the
  * form "@@ -a,b +c,d @@"

@@ -1013,6 +1058,9 @@ 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))
+		return -1;
 	oldlines = fragment->oldlines;
 	newlines = fragment->newlines;
 	leading = 0;

@@ -2912,7 +2960,8 @@ 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 recount)
 {
 	size_t offset;
 	struct strbuf buf;

@@ -2929,6 +2978,7 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
 
 		patch = xcalloc(1, sizeof(*patch));
 		patch->inaccurate_eof = inaccurate_eof;
+		patch->recount = recount;
 		nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
 		if (nr < 0)
 			break;

@@ -2998,6 +3048,7 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 	int i;
 	int read_stdin = 1;
 	int inaccurate_eof = 0;
+	int recount = 0;
 	int errs = 0;
 	int is_not_gitdir;
 

@@ -3015,7 +3066,8 @@ 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,
+					recount);
 			read_stdin = 0;
 			continue;
 		}

@@ -3118,6 +3170,10 @@ int cmd_apply(int argc, const char **argv, const char *unused_prefix)
 			inaccurate_eof = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--recount")) {
+			recount = 1;
+			continue;
+		}
 		if (0 < prefix_length)
 			arg = prefix_filename(prefix, prefix_length, arg);
 

@@ -3126,12 +3182,12 @@ 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, recount);
 		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, recount);
 	if (whitespace_error) {
 		if (squelch_whitespace_errors &&
 		    squelch_whitespace_errors < whitespace_error) {