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![Jeff King](/assets/img/avatar_default.png)
The prefix_filename() function returns a pointer to static storage, which makes it easy to use dangerously. We already fixed one buggy caller in hash-object recently, and the calls in apply.c are suspicious (I didn't dig in enough to confirm that there is a bug, but we call the function once in apply_all_patches() and then again indirectly from parse_chunk()). Let's make it harder to get wrong by allocating the return value. For simplicity, we'll do this even when the prefix is empty (and we could just return the original file pointer). That will cause us to allocate sometimes when we wouldn't otherwise need to, but this function isn't called in performance critical code-paths (and it already _might_ allocate on any given call, so a caller that cares about performance is questionable anyway). The downside is that the callers need to remember to free() the result to avoid leaking. Most of them already used xstrdup() on the result, so we know they are OK. The remainder have been converted to use free() as appropriate. I considered retaining a prefix_filename_unsafe() for cases where we know the static lifetime is OK (and handling the cleanup is awkward). This is only a handful of cases, though, and it's not worth the mental energy in worrying about whether the "unsafe" variant is OK to use in any situation. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
159 lines
4.3 KiB
C
159 lines
4.3 KiB
C
/*
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* GIT - The information manager from hell
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*
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* Copyright (C) Linus Torvalds, 2005
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* Copyright (C) Junio C Hamano, 2005
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*/
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#include "builtin.h"
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#include "blob.h"
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#include "quote.h"
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#include "parse-options.h"
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#include "exec_cmd.h"
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/*
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* This is to create corrupt objects for debugging and as such it
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* needs to bypass the data conversion performed by, and the type
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* limitation imposed by, index_fd() and its callees.
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*/
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static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigned flags)
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{
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struct strbuf buf = STRBUF_INIT;
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int ret;
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if (strbuf_read(&buf, fd, 4096) < 0)
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ret = -1;
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else
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ret = hash_sha1_file_literally(buf.buf, buf.len, type, sha1, flags);
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strbuf_release(&buf);
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return ret;
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}
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static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
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int literally)
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{
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struct stat st;
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unsigned char sha1[20];
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if (fstat(fd, &st) < 0 ||
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(literally
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? hash_literally(sha1, fd, type, flags)
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: index_fd(sha1, fd, &st, type_from_string(type), path, flags)))
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die((flags & HASH_WRITE_OBJECT)
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? "Unable to add %s to database"
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: "Unable to hash %s", path);
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printf("%s\n", sha1_to_hex(sha1));
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maybe_flush_or_die(stdout, "hash to stdout");
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}
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static void hash_object(const char *path, const char *type, const char *vpath,
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unsigned flags, int literally)
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{
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int fd;
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fd = open(path, O_RDONLY);
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if (fd < 0)
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die_errno("Cannot open '%s'", path);
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hash_fd(fd, type, vpath, flags, literally);
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}
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static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
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int literally)
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{
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struct strbuf buf = STRBUF_INIT;
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struct strbuf unquoted = STRBUF_INIT;
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while (strbuf_getline(&buf, stdin) != EOF) {
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if (buf.buf[0] == '"') {
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strbuf_reset(&unquoted);
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if (unquote_c_style(&unquoted, buf.buf, NULL))
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die("line is badly quoted");
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strbuf_swap(&buf, &unquoted);
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}
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hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
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literally);
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}
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strbuf_release(&buf);
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strbuf_release(&unquoted);
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}
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int cmd_hash_object(int argc, const char **argv, const char *prefix)
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{
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static const char * const hash_object_usage[] = {
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N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters] [--stdin] [--] <file>..."),
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N_("git hash-object --stdin-paths"),
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NULL
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};
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const char *type = blob_type;
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int hashstdin = 0;
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int stdin_paths = 0;
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int no_filters = 0;
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int literally = 0;
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int nongit = 0;
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unsigned flags = HASH_FORMAT_CHECK;
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const char *vpath = NULL;
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const struct option hash_object_options[] = {
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OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
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OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
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HASH_WRITE_OBJECT),
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OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
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OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
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OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
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OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
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OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
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OPT_END()
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};
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int i;
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const char *errstr = NULL;
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argc = parse_options(argc, argv, NULL, hash_object_options,
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hash_object_usage, 0);
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if (flags & HASH_WRITE_OBJECT)
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prefix = setup_git_directory();
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else
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prefix = setup_git_directory_gently(&nongit);
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if (vpath && prefix)
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vpath = xstrdup(prefix_filename(prefix, vpath));
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git_config(git_default_config, NULL);
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if (stdin_paths) {
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if (hashstdin)
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errstr = "Can't use --stdin-paths with --stdin";
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else if (argc)
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errstr = "Can't specify files with --stdin-paths";
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else if (vpath)
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errstr = "Can't use --stdin-paths with --path";
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}
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else {
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if (hashstdin > 1)
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errstr = "Multiple --stdin arguments are not supported";
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if (vpath && no_filters)
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errstr = "Can't use --path with --no-filters";
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}
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if (errstr) {
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error("%s", errstr);
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usage_with_options(hash_object_usage, hash_object_options);
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}
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if (hashstdin)
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hash_fd(0, type, vpath, flags, literally);
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for (i = 0 ; i < argc; i++) {
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const char *arg = argv[i];
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char *to_free = NULL;
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if (prefix)
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arg = to_free = prefix_filename(prefix, arg);
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hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
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flags, literally);
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free(to_free);
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}
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if (stdin_paths)
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hash_stdin_paths(type, no_filters, flags, literally);
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return 0;
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}
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