7-Zip: Set error message when seeking fails

Avoid (null) error message when seeking fails (e.g. on filtered
streams).

Fixes #2956

diff --git a/libarchive/archive_read_support_format_7zip.c b/libarchive/archive_read_support_format_7zip.c
index 52cbfd683e67db4f2d70106a2e77b7cd15b15664..2f1ab7d75b782da20eb0f92617a9f9e30818d545 100644 (file)
--- a/libarchive/archive_read_support_format_7zip.c
+++ b/libarchive/archive_read_support_format_7zip.c
@@ -729,6 +729,7 @@ get_pe_sfx_offset(struct archive_read *a, int64_t *sfx_offset)
 static int
 get_elf_sfx_offset(struct archive_read *a, int64_t *sfx_offset)
 {
+       int64_t r;
        const char *h;
        char big_endian, format_64;
        ssize_t bytes;
@@ -795,6 +796,7 @@ get_elf_sfx_offset(struct archive_read *a, int64_t *sfx_offset)
                 * Reading the section table to find strtab section
                 */
                if (__archive_read_seek(a, e_shoff, SEEK_SET) < 0) {
+                       archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
                        return (ARCHIVE_FATAL);
                }
                if (format_64) {
@@ -828,6 +830,7 @@ get_elf_sfx_offset(struct archive_read *a, int64_t *sfx_offset)
                 * Read the STRTAB section to find the .data offset
                 */
                if (__archive_read_seek(a, strtab_offset, SEEK_SET) < 0) {
+                       archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
                        return (ARCHIVE_FATAL);
                }
                h = __archive_read_ahead(a, strtab_size, NULL);
@@ -849,6 +852,7 @@ get_elf_sfx_offset(struct archive_read *a, int64_t *sfx_offset)
                 * Find the section with the .data name
                 */
                if (__archive_read_seek(a, e_shoff, SEEK_SET) < 0) {
+                       archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
                        return (ARCHIVE_FATAL);
                }
                h = __archive_read_ahead(a, (size_t)e_shnum * e_shentsize, NULL);
@@ -880,7 +884,10 @@ get_elf_sfx_offset(struct archive_read *a, int64_t *sfx_offset)
                break;
        }
 
-       return __archive_read_seek(a, 0, SEEK_SET);
+       r = __archive_read_seek(a, 0, SEEK_SET);
+       if (r < 0)
+               archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
+       return (int)r;
 }
 
 static int
@@ -3261,8 +3268,10 @@ slurp_central_directory(struct archive_read *a, struct _7zip *zip,
 
        if (get_data_offset(a, &data_offset) < 0)
                return (ARCHIVE_FATAL);
-       if (__archive_read_consume(a, data_offset) < 0)
+       if (__archive_read_consume(a, data_offset) < 0) {
+               archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
                return (ARCHIVE_FATAL);
+       }
        if ((p = __archive_read_ahead(a, 32, &bytes_avail)) == NULL)
                return (ARCHIVE_FATAL);
 
@@ -3299,8 +3308,10 @@ slurp_central_directory(struct archive_read *a, struct _7zip *zip,
                if (bytes_avail >= (ssize_t)next_header_offset)
                        __archive_read_consume(a, next_header_offset);
                else if (__archive_read_seek(a,
-                   next_header_offset + zip->seek_base, SEEK_SET) < 0)
+                   next_header_offset + zip->seek_base, SEEK_SET) < 0) {
+                       archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
                        return (ARCHIVE_FATAL);
+               }
        }
        zip->stream_offset = next_header_offset;
        zip->header_offset = next_header_offset;
@@ -3637,8 +3648,10 @@ seek_pack(struct archive_read *a)
        pack_offset = zip->si.pi.positions[zip->pack_stream_index];
        if (zip->stream_offset != pack_offset) {
                if (0 > __archive_read_seek(a, pack_offset + zip->seek_base,
-                   SEEK_SET))
+                   SEEK_SET)) {
+                       archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, "Seek error");
                        return (ARCHIVE_FATAL);
+               }
                zip->stream_offset = pack_offset;
        }
        zip->pack_stream_index++;