Bug 12816 - grep does not match GNU grep for -xf EMPTY_FILE
Summary: grep does not match GNU grep for -xf EMPTY_FILE
Status: RESOLVED FIXED
Alias: None
Product: Busybox
Classification: Unclassified
Component: Other (show other bugs)
Version: 1.32.x
Hardware: All Linux
: P5 normal
Target Milestone: ---
Assignee: unassigned
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-04-27 12:22 UTC by wolf+busybox
Modified: 2020-04-29 22:22 UTC (History)
1 user (show)

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Description wolf+busybox 2020-04-27 12:22:32 UTC 
Hello,

while implementing whitelist mechanism in my shell scripting, I've
noticed an inconsistency between busybox's grep and GNU grep. They
handle -xf EMPTY_FILE flags differently when EMPTY_FILE is well...
empty.

GNU grep in that case handles it as if /.*/ pattern was provided, while
busybox uses //.

Attached patch fixes this issue. I've both added a test case into grep's
testsuite and I've also used following shell script to verify that the
behavior does match now:

http://lists.busybox.net/pipermail/busybox/2020-April/087915.html
Comment 1 Denys Vlasenko 2020-04-29 22:22:00 UTC 
Fixed in git