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author | kientzle <kientzle@FreeBSD.org> | 2008-01-23 05:47:08 +0000 |
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committer | kientzle <kientzle@FreeBSD.org> | 2008-01-23 05:47:08 +0000 |
commit | d164e15296c449484a5a6fc7ccb457614a31f943 (patch) | |
tree | 3a362cd06cd0e8bdfcc3e1df6acf218d3bf3635b /lib/libarchive/test | |
parent | 5c89a8c35ace87aee90e7348a11456d06092dcc2 (diff) | |
download | FreeBSD-src-d164e15296c449484a5a6fc7ccb457614a31f943.zip FreeBSD-src-d164e15296c449484a5a6fc7ccb457614a31f943.tar.gz |
Explain a subtle API change that was made recently.
Even though I believe this is a good change, it does
have the potential to break certain clients, so it's
good to document the reasoning behind the change.
Diffstat (limited to 'lib/libarchive/test')
-rw-r--r-- | lib/libarchive/test/test_write_disk.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/libarchive/test/test_write_disk.c b/lib/libarchive/test/test_write_disk.c index ed83109..ddad9b6 100644 --- a/lib/libarchive/test/test_write_disk.c +++ b/lib/libarchive/test/test_write_disk.c @@ -60,6 +60,23 @@ static void create_reg_file(struct archive_entry *ae, const char *msg) /* Write the entry to disk. */ assert((ad = archive_write_disk_new()) != NULL); failure("%s", msg); + /* + * A touchy API design issue: archive_write_data() does (as of + * 2.4.12) enforce the entry size as a limit on the data + * written to the file. This was not enforced prior to + * 2.4.12. The change was prompted by the refined + * hardlink-restore semantics introduced at that time. In + * short, libarchive needs to know whether a "hardlink entry" + * is going to overwrite the contents so that it can know + * whether or not to open the file for writing. This implies + * that there is a fundamental semantic difference between an + * entry with a zero size and one with a non-zero size in the + * case of hardlinks and treating the hardlink case + * differently from the regular file case is just asking for + * trouble. So, a zero size must always mean that no data + * will be accepted, which is consistent with the file size in + * the entry being a maximum size. + */ archive_entry_set_size(ae, sizeof(data)); assertEqualIntA(ad, 0, archive_write_header(ad, ae)); assertEqualInt(sizeof(data), archive_write_data(ad, data, sizeof(data))); @@ -93,6 +110,10 @@ static void create_reg_file2(struct archive_entry *ae, const char *msg) /* Write the entry to disk. */ assert((ad = archive_write_disk_new()) != NULL); failure("%s", msg); + /* + * See above for an explanation why this next call + * is necessary. + */ archive_entry_set_size(ae, datasize); assertEqualIntA(ad, 0, archive_write_header(ad, ae)); for (i = 0; i < datasize - 999; i += 1000) { |