od: fix a bug that arises when skipping exact length of file

* NEWS: Document the bug fix.
* src/od.c (skip): Call fseek even when n_skip is exactly the
same as the length of the current file.  Otherwise, the next
iteration would use unadjusted input stream pointer, thus ignoring
the desired "skip".  Report and patch by Paul GHALEB.

4 files changed, 19 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 1cd7390b4..df1718e74 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2007-08-14  Jim Meyering  <jim@meyering.net>
+
+	od: fix a bug that arises when skipping exact length of file
+	* NEWS: Document the bug fix.
+	* src/od.c (skip): Call fseek even when n_skip is exactly the
+	same as the length of the current file.  Otherwise, the next
+	iteration would use unadjusted input stream pointer, thus ignoring
+	the desired "skip".  Report and patch by Paul GHALEB.
+
 2007-08-10  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Accommodate more xstrtol changes.
diff --git a/NEWS b/NEWS
index 83d06b753..13d3402f1 100644
--- a/NEWS
+++ b/NEWS
@@ -98,6 +98,11 @@ GNU coreutils NEWS                                    -*- outline -*-
   ln=target attribute) would mistakenly output the string "target"
   before the name of each symlink.  [introduced in coreutils-6.0]
 
+  "od -j L FILE" had a bug: when the number of bytes to skip, L, is exactly
+  the same as the length of FILE, od would skip *no* bytes.  When the number
+  of bytes to skip is exactly the sum of the lengths of the first N files,
+  od would skip only the first N-1 files. [introduced in textutils-2.0.9]
+
   seq no longer mishandles obvious cases like "seq 0 0.000001 0.000003",
   so workarounds like "seq 0 0.000001 0.0000031" are no longer needed.
 
diff --git a/THANKS b/THANKS
index ae5269f31..cdddec497 100644
--- a/THANKS
+++ b/THANKS
@@ -397,6 +397,7 @@ Oskar Liljeblad                     osk@hem.passagen.se
 Pádraig Brady                       P@draigBrady.com
 Patrick Mauritz                     oxygene@studentenbude.ath.cx
 Paul Eggert                         eggert@twinsun.com
+Paul Ghaleb                         paul.ghaleb@st.com
 Paul Jarc                           prj@po.cwru.edu
 Paul Nevai                          nevai@ops.mps.ohio-state.edu
 Paul Sauer                          paul@alexa.com
diff --git a/src/od.c b/src/od.c
index 1e77f9208..0abce599a 100644
--- a/src/od.c
+++ b/src/od.c
@@ -1034,13 +1034,12 @@ skip (uintmax_t n_skip)
 	{
 	  /* The st_size field is valid only for regular files
 	     (and for symbolic links, which cannot occur here).
-	     If the number of bytes left to skip is at least
-	     as large as the size of the current file, we can
-	     decrement n_skip and go on to the next file.  */
-
+	     If the number of bytes left to skip is larger than
+	     the size of the current file, we can decrement
+	     n_skip and go on to the next file.  */
 	  if (S_ISREG (file_stats.st_mode) && 0 <= file_stats.st_size)
 	    {
-	      if ((uintmax_t) file_stats.st_size <= n_skip)
+	      if ((uintmax_t) file_stats.st_size < n_skip)
 		n_skip -= file_stats.st_size;
 	      else
 		{