Merge 'cat-file-smudge'

This topic branch adds support to cat-file to apply the smudge filter
(if any) when showing blobs.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

Documentation/git-cat-file.txt

@@ -9,15 +9,15 @@ git-cat-file - Provide content or type and size information for repository objec
 SYNOPSIS
 --------
 [verse]
-'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv ) <object>
+'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv | --smudge ) <object>
 'git cat-file' (--batch | --batch-check) [--follow-symlinks]
 
 DESCRIPTION
 -----------
 In its first form, the command provides the content or the type of an object in
 the repository. The type is required unless `-t` or `-p` is used to find the
-object type, or `-s` is used to find the object size, or `--textconv` is used
-(which implies type "blob").
+object type, or `-s` is used to find the object size, or `--textconv` or
+`--smudge` is used (which imply type "blob").
 
 In the second form, a list of objects (separated by linefeeds) is provided on
 stdin, and the SHA-1, type, and size of each object is printed on stdout.
@@ -54,8 +54,14 @@ OPTIONS
 
 --textconv::
 	Show the content as transformed by a textconv filter. In this case,
-	<object> has be of the form <tree-ish>:<path>, or :<path> in order
-	to apply the filter to the content recorded in the index at <path>.
+	<object> has to be of the form <tree-ish>:<path>, or :<path> in
+	order to apply the filter to the content recorded in the index at
+	<path>.
+
+--smudge::
+	Show the content as transformed by the smudge filter configured in
+	the current working tree for the given <path>. In this case,
+	<object> has to be of the form <tree-ish>:<path>, or :<path>.
 
 --batch::
 --batch=<format>::

builtin/cat-file.c

@@ -20,6 +20,32 @@ struct batch_options {
 	const char *format;
 };
 
+static int smudge_object(const char *path, unsigned mode, unsigned char *sha1,
+	char **buf, unsigned long *size)
+{
+	enum object_type type;
+
+	*buf = read_sha1_file(sha1, &type, size);
+	if (!*buf)
+		return error(_("cannot read object %s '%s'"),
+			sha1_to_hex(sha1), path);
+	if (type != OBJ_BLOB) {
+		free(*buf);
+		return error(_("blob expected for %s '%s'"),
+			sha1_to_hex(sha1), path);
+	}
+	if (S_ISREG(mode)) {
+		struct strbuf strbuf = STRBUF_INIT;
+		if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
+			free(*buf);
+			*size = strbuf.len;
+			*buf = strbuf_detach(&strbuf, NULL);
+		}
+	}
+
+	return 0;
+}
+
 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 			int unknown_type)
 {
@@ -61,6 +87,15 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 	case 'e':
 		return !has_sha1_file(sha1);
 
+	case 'w':
+		if (!obj_context.path[0])
+			die("git cat-file --smudge %s: <object> must be <sha1:path>",
+			    obj_name);
+
+		if (smudge_object(obj_context.path, obj_context.mode, sha1, &buf, &size))
+			return -1;
+		break;
+
 	case 'c':
 		if (!obj_context.path[0])
 			die("git cat-file --textconv %s: <object> must be <sha1:path>",
@@ -440,7 +475,7 @@ static int batch_objects(struct batch_options *opt)
 }
 
 static const char * const cat_file_usage[] = {
-	N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
+	N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv|--smudge) <object>"),
 	N_("git cat-file (--batch | --batch-check) [--follow-symlinks]"),
 	NULL
 };
@@ -486,6 +521,8 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 		OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 		OPT_CMDMODE(0, "textconv", &opt,
 			    N_("for blob objects, run textconv on object's content"), 'c'),
+		OPT_CMDMODE(0, "smudge", &opt,
+			    N_("for blob objects, run smudge filters on object's content"), 'w'),
 		OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 			  N_("allow -s and -t to work with broken/corrupt objects")),
 		OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),

t/t8010-cat-file-filters.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+test_description='git cat-file filters support'
+. ./test-lib.sh
+
+test_expect_success 'setup ' '
+	echo "*.txt eol=crlf" >.gitattributes &&
+	echo "hello" | append_cr >world.txt &&
+	git add .gitattributes world.txt &&
+	test_tick &&
+	git commit -m "Initial commit"
+'
+
+has_cr() {
+	tr '\015' Q <"$1" | grep Q >/dev/null
+}
+
+test_expect_success 'no filters with `git show`' '
+	git show HEAD:world.txt >actual &&
+	! has_cr actual
+
+'
+
+test_expect_success 'no filters with cat-file' '
+	git cat-file blob HEAD:world.txt >actual &&
+	! has_cr actual
+'
+
+test_expect_success 'cat-file --smudge converts to worktree version' '
+	git cat-file --smudge HEAD:world.txt >actual &&
+	has_cr actual
+'
+
+test_done