From cf3c6352100a0d302276e46e3f9a7f0804e224d8 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 12 Dec 2016 14:52:22 -0500 Subject: alternates: accept double-quoted paths We read lists of alternates from objects/info/alternates files (delimited by newline), as well as from the GIT_ALTERNATE_OBJECT_DIRECTORIES environment variable (delimited by colon or semi-colon, depending on the platform). There's no mechanism for quoting the delimiters, so it's impossible to specify an alternate path that contains a colon in the environment, or one that contains a newline in a file. We've lived with that restriction for ages because both alternates and filenames with colons are relatively rare, and it's only a problem when the two meet. But since 722ff7f87 (receive-pack: quarantine objects until pre-receive accepts, 2016-10-03), which builds on the alternates system, every push causes the receiver to set GIT_ALTERNATE_OBJECT_DIRECTORIES internally. It would be convenient to have some way to quote the delimiter so that we can represent arbitrary paths. The simplest thing would be an escape character before a quoted delimiter (e.g., "\:" as a literal colon). But that creates a backwards compatibility problem: any path which uses that escape character is now broken, and we've just shifted the problem. We could choose an unlikely escape character (e.g., something from the non-printable ASCII range), but that's awkward to use. Instead, let's treat names as unquoted unless they begin with a double-quote, in which case they are interpreted via our usual C-stylke quoting rules. This also breaks backwards-compatibility, but in a smaller way: it only matters if your file has a double-quote as the very _first_ character in the path (whereas an escape character is a problem anywhere in the path). It's also consistent with many other parts of git, which accept either a bare pathname or a double-quoted one, and the sender can choose to quote or not as required. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- sha1_file.c | 47 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 36 insertions(+), 11 deletions(-) (limited to 'sha1_file.c') diff --git a/sha1_file.c b/sha1_file.c index fbafdbed94..fc6d864fda 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -26,6 +26,7 @@ #include "mru.h" #include "list.h" #include "mergesort.h" +#include "quote.h" #ifndef O_NOATIME #if defined(__linux__) && (defined(__i386__) || defined(__PPC__)) @@ -329,13 +330,40 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base, return 0; } +static const char *parse_alt_odb_entry(const char *string, + int sep, + struct strbuf *out) +{ + const char *end; + + strbuf_reset(out); + + if (*string == '#') { + /* comment; consume up to next separator */ + end = strchrnul(string, sep); + } else if (*string == '"' && !unquote_c_style(out, string, &end)) { + /* + * quoted path; unquote_c_style has copied the + * data for us and set "end". Broken quoting (e.g., + * an entry that doesn't end with a quote) falls + * back to the unquoted case below. + */ + } else { + /* normal, unquoted path */ + end = strchrnul(string, sep); + strbuf_add(out, string, end - string); + } + + if (*end) + end++; + return end; +} + static void link_alt_odb_entries(const char *alt, int len, int sep, const char *relative_base, int depth) { - struct string_list entries = STRING_LIST_INIT_NODUP; - char *alt_copy; - int i; struct strbuf objdirbuf = STRBUF_INIT; + struct strbuf entry = STRBUF_INIT; if (depth > 5) { error("%s: ignoring alternate object stores, nesting too deep.", @@ -348,16 +376,13 @@ static void link_alt_odb_entries(const char *alt, int len, int sep, die("unable to normalize object directory: %s", objdirbuf.buf); - alt_copy = xmemdupz(alt, len); - string_list_split_in_place(&entries, alt_copy, sep, -1); - for (i = 0; i < entries.nr; i++) { - const char *entry = entries.items[i].string; - if (entry[0] == '\0' || entry[0] == '#') + while (*alt) { + alt = parse_alt_odb_entry(alt, sep, &entry); + if (!entry.len) continue; - link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf); + link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf); } - string_list_clear(&entries, 0); - free(alt_copy); + strbuf_release(&entry); strbuf_release(&objdirbuf); } -- cgit v1.2.1