initial cleanup of tar readahead/consume pairing; not finished (read_header is a...

SVN-Revision: 2696

diff --git a/libarchive/archive_read_support_format_tar.c b/libarchive/archive_read_support_format_tar.c
index c5204cbd406427723ffd1e5fe48fc3b411e920d9..0a3fd86331fedcbac84e46261661e599d53bf275 100644 (file)
--- a/libarchive/archive_read_support_format_tar.c
+++ b/libarchive/archive_read_support_format_tar.c
@@ -163,6 +163,7 @@ struct tar {
        int64_t                  entry_bytes_remaining;
        int64_t                  entry_offset;
        int64_t                  entry_padding;
+       int64_t                  entry_bytes_unconsumed;
        int64_t                  realsize;
        struct sparse_block     *sparse_list;
        struct sparse_block     *sparse_last;
@@ -253,13 +254,12 @@ archive_read_support_format_tar(struct archive *_a)
        archive_check_magic(_a, ARCHIVE_READ_MAGIC,
            ARCHIVE_STATE_NEW, "archive_read_support_format_tar");
 
-       tar = (struct tar *)malloc(sizeof(*tar));
+       tar = (struct tar *)calloc(1, sizeof(*tar));
        if (tar == NULL) {
                archive_set_error(&a->archive, ENOMEM,
                    "Can't allocate tar data");
                return (ARCHIVE_FATAL);
        }
-       memset(tar, 0, sizeof(*tar));
 
        r = __archive_read_register_format(a, tar, "tar",
            archive_read_format_tar_bid,
@@ -470,6 +470,11 @@ archive_read_format_tar_read_data(struct archive_read *a,
                free(p);
        }
 
+       if (tar->entry_bytes_unconsumed) {
+               __archive_read_consume(a, tar->entry_bytes_unconsumed);
+               tar->entry_bytes_unconsumed = 0;
+       }
+
        /* If we're at end of file, return EOF. */
        if (tar->sparse_list == NULL || tar->entry_bytes_remaining == 0) {
                if (__archive_read_consume(a, tar->entry_padding) < 0)
@@ -500,7 +505,7 @@ archive_read_format_tar_read_data(struct archive_read *a,
        tar->sparse_list->remaining -= bytes_read;
        tar->sparse_list->offset += bytes_read;
        tar->entry_bytes_remaining -= bytes_read;
-       __archive_read_consume(a, bytes_read);
+       tar->entry_bytes_unconsumed = bytes_read;
        return (ARCHIVE_OK);
 }
 
@@ -513,11 +518,13 @@ archive_read_format_tar_skip(struct archive_read *a)
        tar = (struct tar *)(a->format->data);
 
        bytes_skipped = __archive_read_consume(a,
-           tar->entry_bytes_remaining + tar->entry_padding);
+           tar->entry_bytes_remaining + tar->entry_padding + 
+           tar->entry_bytes_unconsumed);
        if (bytes_skipped < 0)
                return (ARCHIVE_FATAL);
 
        tar->entry_bytes_remaining = 0;
+       tar->entry_bytes_unconsumed = 0;
        tar->entry_padding = 0;
 
        /* Free the sparse list. */
@@ -545,6 +552,7 @@ tar_read_header(struct archive_read *a, struct tar *tar,
                return (bytes);
        if (bytes < 512) {  /* Short read or EOF. */
                /* Try requesting just one byte and see what happens. */
+               /* XXX: Harring notes, this should be impossible to be anything but EOF... */
                (void)__archive_read_ahead(a, 1, &bytes);
                if (bytes == 0) {
                        /*
@@ -560,12 +568,11 @@ tar_read_header(struct archive_read *a, struct tar *tar,
                    "Truncated tar archive");
                return (ARCHIVE_FATAL);
        }
-       __archive_read_consume(a, 512);
-
 
        /* Check for end-of-archive mark. */
        if (((*(const char *)h)==0) && archive_block_is_null((const unsigned char *)h)) {
                /* Try to consume a second all-null record, as well. */
+               __archive_read_consume(a, 512);
                h = __archive_read_ahead(a, 512, NULL);
                if (h != NULL)
                        __archive_read_consume(a, 512);
@@ -585,17 +592,22 @@ tar_read_header(struct archive_read *a, struct tar *tar,
         * TODO: Improve this by implementing a real header scan.
         */
        if (!checksum(a, h)) {
+               __archive_read_consume(a, 512);
                archive_set_error(&a->archive, EINVAL, "Damaged tar archive");
                return (ARCHIVE_RETRY); /* Retryable: Invalid header */
        }
 
        if (++tar->header_recursion_depth > 32) {
+               __archive_read_consume(a, 512);
                archive_set_error(&a->archive, EINVAL, "Too many special headers");
                return (ARCHIVE_WARN);
        }
 
        /* Determine the format variant. */
        header = (const struct archive_entry_header_ustar *)h;
+
+       __archive_read_consume(a, 512);
+
        switch(header->typeflag[0]) {
        case 'A': /* Solaris tar ACL */
                a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;