Bug introduced in ed v1.14 (up to v1.19) corrupting full file which delta changes are applied to

[Danie Theron - DSV]

Good day Antonio and other maintainers of ed,

We are using a software version control system which our developers are using 
to make changes to programs and deploy to different environments.
The back end of the application is using Unix/Linux commands to manipulate & 
reconstructing programs. The main commands are "diff" and "ed".
For example when a program is created on the system, it stores the full content 
of v1.0 in the database.

When changes are made to the initial version of the v1.0 program, only the 
delta changes (generated from the "diff" command) v1.1, v1.2, v1.3 and so forth 
is stored in the database so that the database does not grow excessively by 
storing the full contents of the modified program versions. 

When the program is continually modified or gets deployed to an environment, it 
uses "ed" to reconstruct the specific version of the program, the deltas are 
applied to the v1.0 program.

This is working fine up to v1.13 of "ed", but since v1.14 up to the latest 
version v1.19, the deltas are not being applied correctly causing corruption in 
the reconstruction of programs.

(We have migrated from Solaris 11.4 using an ancient version of "ed" - version 
unknown, to RHEL 8 which uses "ed" version 1.14.2, which corrupted a lot of our 
programs. As an interim solution I have compiled v1.13 of "ed", and updated the 
system scripts to use "ed" v1.13)

Can you please find the cause and release a bugfix version that solves this 
issue?

Please see my test cases below & attached:

# cat textfile_v1.0.txt
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG

# cat textfile_v1.1.txt
AAAAAAAAAAAAAAAAXAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
EEEEEEEEEEEEEEEEEEEEEEZEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG

# cat textfile_v1.2.txt
AAAAAAAAAAAAAAAAXAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
EEEEEEEEEEEEEEEEEEEEEEZEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
SGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG

# cat textfile_v1.3.txt
AAAAAAAAAAAAAAAAXAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBHBBBBBBBB
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
EEEEEEEEEEEEEEEEEEEEEEZEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
SGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG

# diff -e textfile_v1.0.txt textfile_v1.1.txt > textfile_v1.1_delta.txt

# cat textfile_v1.1_delta.txt
5c
EEEEEEEEEEEEEEEEEEEEEEZEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
.
1c
AAAAAAAAAAAAAAAAXAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
.

# diff -e textfile_v1.1.txt textfile_v1.2.txt > textfile_v1.2_delta.txt

# cat textfile_v1.2_delta.txt
7c
SGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
.
3a

.

# diff -e textfile_v1.2.txt textfile_v1.3.txt > textfile_v1.3_delta.txt

# cat textfile_v1.3_delta.txt
7c
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
.
2c
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBHBBBBBBBB
.

##############################################################
# ---> ed version 1.13 <----                                 #
# Reconstruct v1.3 of the file using version 1.0 of the file #
# and applying the v1.1, v1.2 & v1.3 delta files             #
##############################################################

# /home/userabc/ed/ed-1.13/ed -V
GNU ed 1.13
Copyright (C) 1994 Andrew L. Moore.
Copyright (C) 2016 Antonio Diaz Diaz.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

# (cat textfile_v1.1_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.13/ed - 
textfile_v1.0.txt > textfile_v1.1_reconstructed.txt
# (cat textfile_v1.2_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.13/ed - 
textfile_v1.1_reconstructed.txt > textfile_v1.2_reconstructed.txt
# (cat textfile_v1.3_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.13/ed - 
textfile_v1.2_reconstructed.txt > textfile_v1.3_reconstructed.txt
#
# diff textfile_v1.3.txt textfile_v1.3_reconstructed.txt
#
>>>>> GREAT - successfully reconstructed v1.3 using the full v1.0 and applying 
>>>>> the v1.1, v1.2 & v1.3 deltas


##############################################################
# ---> ed version 1.14 <----                                 #
# Reconstruct v1.3 of the file using version 1.0 of the file #
# and applying the v1.1, v1.2 & v1.3 delta files             #
##############################################################

# /home/userabc/ed/ed-1.14/ed -V
GNU ed 1.14
Copyright (C) 1994 Andrew L. Moore.
Copyright (C) 2017 Antonio Diaz Diaz.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

# (cat textfile_v1.1_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.14/ed - 
textfile_v1.0.txt > textfile_v1.1_reconstructed.txt
# diff textfile_v1.1.txt textfile_v1.1_reconstructed.txt
7a8
> ?
# (cat textfile_v1.2_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.14/ed - 
textfile_v1.1_reconstructed.txt > textfile_v1.2_reconstructed.txt
# diff textfile_v1.2.txt textfile_v1.2_reconstructed.txt
8a9,10
> ?
> ?
# (cat textfile_v1.3_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.14/ed - 
textfile_v1.2_reconstructed.txt > textfile_v1.3_reconstructed.txt
# diff textfile_v1.3.txt textfile_v1.3_reconstructed.txt
8a9,11
> ?
> ?
> ?

>>>>> NOT GOOD - ed v1.14 corrupts the reconstructions using the full v1.0 and 
>>>>> applying the v1.1, v1.2 & v1.3 deltas


##############################################################
# ---> ed version 1.19 <----                                 #
# Reconstruct v1.3 of the file using version 1.0 of the file #
# and applying the v1.1, v1.2 & v1.3 delta files             #
##############################################################

# /home/userabc/ed/ed-1.19/ed -V
GNU ed 1.19
Copyright (C) 1994 Andrew L. Moore.
Copyright (C) 2023 Antonio Diaz Diaz.
License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
#
# (cat textfile_v1.1_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.19/ed - 
textfile_v1.0.txt > textfile_v1.1_reconstructed.txt
# diff textfile_v1.1.txt textfile_v1.1_reconstructed.txt
7a8
> ?
# (cat textfile_v1.2_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.19/ed - 
textfile_v1.1_reconstructed.txt > textfile_v1.2_reconstructed.txt
# diff textfile_v1.2.txt textfile_v1.2_reconstructed.txt
8a9,10
> ?
> ?
# (cat textfile_v1.3_delta.txt ; echo '1,$p') | /home/userabc/ed/ed-1.19/ed - 
textfile_v1.2_reconstructed.txt > textfile_v1.3_reconstructed.txt
# diff textfile_v1.3.txt textfile_v1.3_reconstructed.txt
8a9,11
> ?
> ?
> ?

>>>>> ALSO NOT GOOD - latest ed v1.19 still corrupts the reconstructions using 
>>>>> the full v1.0 and applying the v1.1, v1.2 & v1.3 deltas


Thank you so much, any help would be much appreciated.


Danie Theron

ed_investigation_duplication.txt
Description: ed_investigation_duplication.txt