gzip: gzip -l now outputs accurate size

gzip -l now decompresses to see how long the uncompressed file was.
This fixes what is by far the most common bug report for gzip.
It has a significant performance cost, but it’s worth it nowadays.
* gzip.c (main): -l now sets 'test' too.  All uses of
'test' changed.
(treat_stdin, treat_file): Call do_list after decompressing,
so that the length is known.
(do_list): Omit arg IFD, since it is no longer needed.
All callers changed.  Get the CRC and uncompressed size
from input_crc and bytes_out instead of using lseek.
* tests/list-big: New test.
* unzip.c (unzip): Set unzip_crc before returning.
* util.c (write_buf): If 'test', output nothing.
Update bytes_out with output byte count, regardless of 'test'.
All callers changed.

1 files changed, 8 insertions, 10 deletions

diff --git a/util.c b/util.c
index 4e73036..cd43886 100644
--- a/util.c
+++ b/util.c
@@ -112,7 +112,6 @@ int copy(in, out)
     errno = 0;
     while (insize > inptr) {
         write_buf(out, (char*)inbuf + inptr, insize - inptr);
-        bytes_out += insize - inptr;
         got = read_buffer (in, (char *) inbuf, INBUFSIZ);
         if (got == -1)
             read_error();
@@ -255,9 +254,7 @@ void flush_outbuf()
 {
     if (outcnt == 0) return;
 
-    if (!test)
-      write_buf (ofd, outbuf, outcnt);
-    bytes_out += (off_t)outcnt;
+    write_buf (ofd, outbuf, outcnt);
     outcnt = 0;
 }
 
@@ -270,16 +267,13 @@ void flush_window()
     if (outcnt == 0) return;
     updcrc(window, outcnt);
 
-    if (!test) {
-        write_buf(ofd, (char *)window, outcnt);
-    }
-    bytes_out += (off_t)outcnt;
+    write_buf (ofd, window, outcnt);
     outcnt = 0;
 }
 
 /* ===========================================================================
- * Does the same as write(), but also handles partial pipe writes and checks
- * for error return.
+ * Update the count of output bytes.  If testing, do not do any
+ * output.  Otherwise, write the buffer, checking for errors.
  */
 void write_buf(fd, buf, cnt)
     int       fd;
@@ -288,6 +282,10 @@ void write_buf(fd, buf, cnt)
 {
     unsigned  n;
 
+    bytes_out += cnt;
+    if (test)
+      return;
+
     while ((n = write_buffer (fd, buf, cnt)) != cnt) {
         if (n == (unsigned)(-1)) {
             write_error();