Merge branch 'jc/hash-object'

"hash-object" learned a new "--literally" option to hash any random
garbage into a loose object, to allow us to create a test data for
mechanisms to catch corrupt objects.

* jc/hash-object:
  hash-object: add --literally option
  hash-object: pass 'write_object' as a flag
  hash-object: reduce file-scope statics

builtin/hash-object.c

@@ -10,35 +10,55 @@
 #include "parse-options.h"
 #include "exec_cmd.h"
 
-static void hash_fd(int fd, const char *type, int write_object, const char *path)
+/*
+ * This is to create corrupt objects for debugging and as such it
+ * needs to bypass the data conversion performed by, and the type
+ * limitation imposed by, index_fd() and its callees.
+ */
+static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigned flags)
+{
+	struct strbuf buf = STRBUF_INIT;
+	int ret;
+
+	if (strbuf_read(&buf, fd, 4096) < 0)
+		ret = -1;
+	else if (flags & HASH_WRITE_OBJECT)
+		ret = write_sha1_file(buf.buf, buf.len, type, sha1);
+	else
+		ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
+	strbuf_release(&buf);
+	return ret;
+}
+
+static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
+		    int literally)
 {
 	struct stat st;
 	unsigned char sha1[20];
-	unsigned flags = (HASH_FORMAT_CHECK |
-			  (write_object ? HASH_WRITE_OBJECT : 0));
 
 	if (fstat(fd, &st) < 0 ||
-	    index_fd(sha1, fd, &st, type_from_string(type), path, flags))
-		die(write_object
+	    (literally
+	     ? hash_literally(sha1, fd, type, flags)
+	     : index_fd(sha1, fd, &st, type_from_string(type), path, flags)))
+		die((flags & HASH_WRITE_OBJECT)
 		    ? "Unable to add %s to database"
 		    : "Unable to hash %s", path);
 	printf("%s\n", sha1_to_hex(sha1));
 	maybe_flush_or_die(stdout, "hash to stdout");
 }
 
-static void hash_object(const char *path, const char *type, int write_object,
-			const char *vpath)
+static void hash_object(const char *path, const char *type, const char *vpath,
+			unsigned flags, int literally)
 {
 	int fd;
 	fd = open(path, O_RDONLY);
 	if (fd < 0)
 		die_errno("Cannot open '%s'", path);
-	hash_fd(fd, type, write_object, vpath);
+	hash_fd(fd, type, vpath, flags, literally);
 }
 
-static int no_filters;
-
-static void hash_stdin_paths(const char *type, int write_objects)
+static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
+			     int literally)
 {
 	struct strbuf buf = STRBUF_INIT, nbuf = STRBUF_INIT;
 
@@ -49,47 +69,46 @@ static void hash_stdin_paths(const char *type, int write_objects)
 				die("line is badly quoted");
 			strbuf_swap(&buf, &nbuf);
 		}
-		hash_object(buf.buf, type, write_objects,
-		    no_filters ? NULL : buf.buf);
+		hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
+			    literally);
 	}
 	strbuf_release(&buf);
 	strbuf_release(&nbuf);
 }
 
-static const char * const hash_object_usage[] = {
-	N_("git hash-object [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin] [--] <file>..."),
-	N_("git hash-object  --stdin-paths < <list-of-paths>"),
-	NULL
-};
-
-static const char *type;
-static int write_object;
-static int hashstdin;
-static int stdin_paths;
-static const char *vpath;
-
-static const struct option hash_object_options[] = {
-	OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
-	OPT_BOOL('w', NULL, &write_object, N_("write the object into the object database")),
-	OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
-	OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
-	OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
-	OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
-	OPT_END()
-};
-
 int cmd_hash_object(int argc, const char **argv, const char *prefix)
 {
+	static const char * const hash_object_usage[] = {
+		N_("git hash-object [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin] [--] <file>..."),
+		N_("git hash-object  --stdin-paths < <list-of-paths>"),
+		NULL
+	};
+	const char *type = blob_type;
+	int hashstdin = 0;
+	int stdin_paths = 0;
+	int no_filters = 0;
+	int literally = 0;
+	unsigned flags = HASH_FORMAT_CHECK;
+	const char *vpath = NULL;
+	const struct option hash_object_options[] = {
+		OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
+		OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
+			HASH_WRITE_OBJECT),
+		OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
+		OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
+		OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
+		OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
+		OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
+		OPT_END()
+	};
 	int i;
 	int prefix_length = -1;
 	const char *errstr = NULL;
 
-	type = blob_type;
-
 	argc = parse_options(argc, argv, NULL, hash_object_options,
 			     hash_object_usage, 0);
 
-	if (write_object) {
+	if (flags & HASH_WRITE_OBJECT) {
 		prefix = setup_git_directory();
 		prefix_length = prefix ? strlen(prefix) : 0;
 		if (vpath && prefix)
@@ -119,19 +138,19 @@ int cmd_hash_object(int argc, const char **argv, const char *prefix)
 	}
 
 	if (hashstdin)
-		hash_fd(0, type, write_object, vpath);
+		hash_fd(0, type, vpath, flags, literally);
 
 	for (i = 0 ; i < argc; i++) {
 		const char *arg = argv[i];
 
 		if (0 <= prefix_length)
 			arg = prefix_filename(prefix, prefix_length, arg);
-		hash_object(arg, type, write_object,
-			    no_filters ? NULL : vpath ? vpath : arg);
+		hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
+			    flags, literally);
 	}
 
 	if (stdin_paths)
-		hash_stdin_paths(type, write_object);
+		hash_stdin_paths(type, no_filters, flags, literally);
 
 	return 0;
 }