From https://ftp.gnu.org/gnu/bash/bash-5.0-patches/bash55-018 Signed-off-by: Peter Korsgaard BASH PATCH REPORT ================= Bash-Release: 5.0 Patch-ID: bash50-018 Bug-Reported-by: oguzismailuysal@gmail.com Bug-Reference-ID: Bug-Reference-URL: https://lists.gnu.org/archive/html/bug-bash/2019-10/msg00098.html Bug-Description: In certain cases, bash does not perform quoted null removal on patterns that are used as part of word expansions such as ${parameter##pattern}, so empty patterns are treated as non-empty. Patch (apply with `patch -p0'): *** bash-5.0.17/subst.c 2020-04-02 17:14:58.000000000 -0400 --- b/subst.c 2020-07-09 15:28:19.000000000 -0400 *************** *** 5113,5116 **** --- b/5113,5118 ---- (int *)NULL, (int *)NULL) : (WORD_LIST *)0; + if (l) + word_list_remove_quoted_nulls (l); pat = string_list (l); dispose_words (l); *** bash-5.0/patchlevel.h 2016-06-22 14:51:03.000000000 -0400 --- b/patchlevel.h 2016-10-01 11:01:28.000000000 -0400 *************** *** 26,30 **** looks for to find the patch level (for the sccs version string). */ ! #define PATCHLEVEL 17 #endif /* _PATCHLEVEL_H_ */ --- b/26,30 ---- looks for to find the patch level (for the sccs version string). */ ! #define PATCHLEVEL 18 #endif /* _PATCHLEVEL_H_ */