sh_reinit(): unset tilde expansion disc (re: 0af8199, 936a193)

Scripts without #! path (e.g., bin/package) incorrectly inherited
.sh.tilde.* discipline functions, affecting tilde expansion.
This is because sh_reinit() fails to reinitialise/unset these.

Just calling _nv_unset for SH_TILDENOD is not enough. For some
reason, the SH_INIT state bit stops _nv_unset() from unsetting
discipline functions associated with variables.

src/cmd/ksh93/sh/init.c: sh_reinit():
- Don't bother with SH_INIT state bit. I don't see the benefit.
- Unset SH_TILDENOD, which now also unsets its disciplines.
- Since _nv_unset() now unsets disciplines, remove separate
  code for zeroing discipline pointers in other variables.

Author: McDutchie

NEWS

@@ -2,6 +2,11 @@ This documents significant changes in the dev branch of ksh 93u+m.
 For full details, see the git log at: https://github.com/ksh93/ksh
 Uppercase BUG_* IDs are shell bug IDs as used by the Modernish shell library.
 
+2024-01-27:
+
+- Fixed: tilde expansion discipline functions (see 2021-03-16) were not
+  reinitialised when executing a ksh script without a #! path line.
+
 2024-01-23:
 
 - Fixed a rare crash or rare incorrect behaviour in .sh.tilde.{get,set}

src/cmd/ksh93/include/version.h

@@ -18,7 +18,7 @@
 
 #define SH_RELEASE_FORK	"93u+m"		/* only change if you develop a new ksh93 fork */
 #define SH_RELEASE_SVER	"1.1.0-alpha"	/* semantic version number: https://semver.org */
-#define SH_RELEASE_DATE	"2024-01-23"	/* must be in this format for $((.sh.version)) */
+#define SH_RELEASE_DATE	"2024-01-27"	/* must be in this format for $((.sh.version)) */
 #define SH_RELEASE_CPYR	"(c) 2020-2024 Contributors to ksh " SH_RELEASE_FORK
 
 /* Scripts sometimes field-split ${.sh.version}, so don't change amount of whitespace. */

src/cmd/ksh93/sh/init.c

@@ -1537,7 +1537,6 @@ int sh_reinit(char *argv[])
 	Dt_t	*dp;
 	int	nofree;
 	char	*savfpath = NULL;
-	sh_onstate(SH_INIT);
 	sh.subshell = sh.realsubshell = sh.comsub = sh.curenv = sh.jobenv = sh.inuse_bits = sh.fn_depth = sh.dot_depth = 0;
 	sh.envlist = NULL;
 	sh.last_root = sh.var_tree;
@@ -1546,6 +1545,8 @@ int sh_reinit(char *argv[])
 		sfclose(sh.heredocs);
 		sh.heredocs = 0;
 	}
+	/* Unset tilde expansion disciplines */
+	_nv_unset(SH_TILDENOD,NV_RDONLY);
 	/* save FPATH and treat specially */
 	if(nv_isattr(FPATHNOD,NV_EXPORT))
 		savfpath = sh_strdup(nv_getval(FPATHNOD));
@@ -1584,9 +1585,6 @@ int sh_reinit(char *argv[])
 			nv_setattr(np,NV_EXPORT);			/* turn off everything except export */
 			if(cp)
 				np->nvalue.cp = cp;			/* replace by string value */
-			/* unset discipline */
-			if(np->nvfun && np->nvfun->disc)
-				np->nvfun->disc = NULL;
 		}
 		else
 		{
@@ -1704,7 +1702,6 @@ int sh_reinit(char *argv[])
 	/* call user init function, if any */
 	if(sh.userinit)
 		(*sh.userinit)(&sh, 1);
-	sh_offstate(SH_INIT);
 	return 1;
 }
 

src/cmd/ksh93/tests/tilde.sh

@@ -2,7 +2,7 @@
 #                                                                      #
 #               This software is part of the ast package               #
 #          Copyright (c) 1982-2012 AT&T Intellectual Property          #
-#          Copyright (c) 2020-2022 Contributors to ksh 93u+m           #
+#          Copyright (c) 2020-2024 Contributors to ksh 93u+m           #
 #                      and is licensed under the                       #
 #                 Eclipse Public License, Version 2.0                  #
 #                                                                      #
@@ -182,5 +182,18 @@ exp=/usr/local/src/ksh93/ksh
 [[ $got == "$exp" ]] || err_exit "error in special builtin disables .sh.tilde discipline" \
 	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 
+# ======
+
+.sh.tilde.set() { print -n BAD; }
+.sh.tilde.get() { .sh.value=' & WRONG'; }
+echo 'echo ~okay' >test.sh
+chmod +x test.sh
+./test.sh >test.out
+got=$(<test.out)
+unset .sh.tilde  # removes discipline functions
+exp=~okay
+[[ $got == "$exp" ]] || err_exit "child script inherits .sh.tilde discipline" \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+
 # ======
 exit $((Errors<125?Errors:125))