[PATCH] wc: fix regression determining file size

[Pádraig Brady]

* src/wc.c (wc): Use off_t rather than size_t
when calculating where to seek to, so that
we don't seek to a too low offset on systems
where size_t < off_t, which would result in
many read() calls to determine the file size.
* tests/misc/wc-proc.sh: Add a test case
sufficient for 32 bit systems at least.
Reported at https://bugs.debian.org/1027101
---
 src/wc.c              | 2 +-
 tests/misc/wc-proc.sh | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/wc.c b/src/wc.c
index bc52a8c0e..df9770396 100644
--- a/src/wc.c
+++ b/src/wc.c
@@ -431,7 +431,7 @@ wc (int fd, char const *file_x, struct fstatus *fstatus, 
off_t current_pos)
       if (! fstatus->failed && usable_st_size (&fstatus->st)
           && 0 <= fstatus->st.st_size)
         {
-          size_t end_pos = fstatus->st.st_size;
+          off_t end_pos = fstatus->st.st_size;
           if (current_pos < 0)
             current_pos = lseek (fd, 0, SEEK_CUR);
 
diff --git a/tests/misc/wc-proc.sh b/tests/misc/wc-proc.sh
index 581890ddd..030872a91 100755
--- a/tests/misc/wc-proc.sh
+++ b/tests/misc/wc-proc.sh
@@ -42,4 +42,11 @@ cat <<\EOF > exp
 EOF
 compare exp out || fail=1
 
+# Ensure we don't read too much when reading,
+# as was the case on 32 bit systems
+# from coreutils-8.24 to coreutils-9.1
+if timeout 10 truncate -s1T do_read; then
+  timeout 10 wc -c do_read || fail=1
+fi
+
 Exit $fail
-- 
2.26.2