Merge branch 'jc/hash-object'

"hash-object --literally" introduced in v2.2 was not prepared to
take a really long object type name.

* jc/hash-object:
write_sha1_file(): do not use a separate sha1[] array
t1007: add hash-object --literally tests
hash-object --literally: fix buffer overrun with extra-long object type
git-hash-object.txt: document --literally option

diff --git a/Documentation/git-hash-object.txt b/Documentation/git-hash-object.txt
index 02c1f126855b24dec121fb49bf920ad14af0b0b8..0c75f3b610678d9a6811ac73d208cabd706b2276 100644 (file)
--- a/Documentation/git-hash-object.txt
+++ b/Documentation/git-hash-object.txt
@@ -9,7 +9,7 @@ git-hash-object - Compute object ID and optionally creates a blob from a file
 SYNOPSIS
 --------
 [verse]
-'git hash-object' [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin] [--] <file>...
+'git hash-object' [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin [--literally]] [--] <file>...
 'git hash-object' [-t <type>] [-w] --stdin-paths [--no-filters] < <list-of-paths>
 
 DESCRIPTION
@@ -51,7 +51,13 @@ OPTIONS
        Hash the contents as is, ignoring any input filter that would
        have been chosen by the attributes mechanism, including the end-of-line
        conversion. If the file is read from standard input then this
-       is always implied, unless the --path option is given.
+       is always implied, unless the `--path` option is given.
+
+--literally::
+       Allow `--stdin` to hash any garbage into a loose object which might not
+       otherwise pass standard object parsing or git-fsck checks. Useful for
+       stress-testing Git itself or reproducing characteristics of corrupt or
+       bogus objects encountered in the wild.
 
 GIT
 ---

diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index 207b90c7b13e103b29305b68aa99d1b9b09342e7..07fef3cc6b832c257bd3256dc6fff3d4c51760d9 100644 (file)
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c
@@ -22,10 +22,8 @@ static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigne
 
        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);
+               ret = hash_sha1_file_literally(buf.buf, buf.len, type, sha1, flags);
        strbuf_release(&buf);
        return ret;
 }

diff --git a/cache.h b/cache.h
index 771b775621595e312484295abd9ca768ece6f6ea..5970940743618fcee3490a2d082b46e934ee2e3d 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -909,6 +909,7 @@ static inline const unsigned char *lookup_replace_object_extended(const unsigned
 extern int sha1_object_info(const unsigned char *, unsigned long *);
 extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
 extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
+extern int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type, unsigned char *sha1, unsigned flags);
 extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
 extern int force_object_loose(const unsigned char *sha1, time_t mtime);
 extern int git_open_noatime(const char *name);

diff --git a/sha1_file.c b/sha1_file.c
index 7634917e4ea934f6673d6d154420499660dbc1ab..866021b2b10ff228a391d38342d7352b1ea779ff 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -3007,9 +3007,8 @@ static int freshen_packed_object(const unsigned char *sha1)
        return 1;
 }
 
-int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
 {
-       unsigned char sha1[20];
        char hdr[32];
        int hdrlen;
 
@@ -3017,13 +3016,32 @@ int write_sha1_file(const void *buf, unsigned long len, const char *type, unsign
         * it out into .git/objects/??/?{38} file.
         */
        write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
-       if (returnsha1)
-               hashcpy(returnsha1, sha1);
        if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
                return 0;
        return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
 }
 
+int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
+                            unsigned char *sha1, unsigned flags)
+{
+       char *header;
+       int hdrlen, status = 0;
+
+       /* type string, SP, %lu of the length plus NUL must fit this */
+       header = xmalloc(strlen(type) + 32);
+       write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
+
+       if (!(flags & HASH_WRITE_OBJECT))
+               goto cleanup;
+       if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
+               goto cleanup;
+       status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
+
+cleanup:
+       free(header);
+       return status;
+}
+
 int force_object_loose(const unsigned char *sha1, time_t mtime)
 {
        void *buf;

diff --git a/t/t1007-hash-object.sh b/t/t1007-hash-object.sh
index ebb3a69c8cd68a51184f809357bb60cb7b35f928..7d2baa15bbd0bbbe8c12631ad2d24b77e90b8775 100755 (executable)
--- a/t/t1007-hash-object.sh
+++ b/t/t1007-hash-object.sh
@@ -209,4 +209,15 @@ test_expect_success 'hash-object complains about truncated type name' '
        test_must_fail git hash-object -t bl --stdin </dev/null
 '
 
+test_expect_success '--literally' '
+       t=1234567890 &&
+       echo example | git hash-object -t $t --literally --stdin
+'
+
+test_expect_success '--literally with extra-long type' '
+       t=12345678901234567890123456789012345678901234567890 &&
+       t="$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t$t" &&
+       echo example | git hash-object -t $t --literally --stdin
+'
+
 test_done