'.': disable ksh function lookup in POSIX mode

POSIXly, '.' loads only files, not functions.

This only applies to '.', not 'source' (which is not in POSIX).

src/cmd/ksh93/bltins/misc.c: b_source():
- For ksh function lookup, add an additional check that we're not
  in POSIX mode and running the '.' (SYSDOT) builtin.

src/cmd/ksh93/bltins/misc.c

@@ -259,7 +259,7 @@ int    b_dot_cmd(register int n,char *argv[],Shbltin_t *context)
 	{
 		/* check for KornShell style function first */
 		np = nv_search(script,shp->fun_tree,0);
-		if(np && is_afunction(np) && !nv_isattr(np,NV_FPOSIX))
+		if(np && is_afunction(np) && !nv_isattr(np,NV_FPOSIX) && !(sh_isoption(SH_POSIX) && shp->bltindata.bnode==SYSDOT))
 		{
 			if(!np->nvalue.ip)
 			{

src/cmd/ksh93/include/version.h

@@ -21,7 +21,7 @@
 
 #define SH_RELEASE_FORK	"93u+m"		/* only change if you develop a new ksh93 fork */
 #define SH_RELEASE_SVER	"1.0.0-beta.2"	/* semantic version number: https://semver.org */
-#define SH_RELEASE_DATE	"2021-11-23"	/* must be in this format for $((.sh.version)) */
+#define SH_RELEASE_DATE	"2021-11-24"	/* must be in this format for $((.sh.version)) */
 #define SH_RELEASE_CPYR	"(c) 2020-2021 Contributors to ksh " SH_RELEASE_FORK
 
 /* Scripts sometimes field-split ${.sh.version}, so don't change amount of whitespace. */

src/cmd/ksh93/sh.1

@@ -7246,6 +7246,9 @@ enables the recognition of a leading zero as introducing an octal number in
 all arithmetic evaluation contexts, except in the \fBlet\fR built-in while
 \fBletoctal\fR is off;
 .IP \[bu]
+stops the \fB.\fR command (but not \fBsource\fR) from looking up functions
+defined with the \fBfunction\fR syntax;
+.IP \[bu]
 changes the \fBtest\fR/\fB[\fR built-in command to make its deprecated
 \fIexpr1\fR \fB-a\fR \fIexpr2\fR and \fIexpr1\fR \fB-o\fR \fIexpr2\fR operators
 work even if \fIexpr1\fR equals "\fB!\fR" or "\fb(\fR" (which means the

src/cmd/ksh93/tests/path.sh

@@ -903,5 +903,22 @@ got=$?
 [[ $exp == $got ]] || err_exit "Test 7E: exit status or error message for exec'd command with long name wrong" \
 	"(expected $exp, got $got)"
 
+# ======
+
+if	[[ -o ?posix ]]
+then	(
+		PATH=/dev/null
+		command set --posix
+		function dottest { :; }
+		. dottest
+	) 2>/dev/null && err_exit "'.' in POSIX mode finds ksh function"
+	(
+		PATH=/dev/null
+		command set --posix
+		function dottest { :; }
+		source dottest
+	) 2>/dev/null || err_exit "'source' in POSIX mode does not find ksh function"
+fi
+
 # ======
 exit $((Errors<125?Errors:125))