whence -a/type -a: report both function and built-in by same name

'whence -a' is documented to list all possible interpretations of a
command, but failed to list a built-in command if a shell function
by the same name exists or is marked undefined using 'autoload'.

src/cmd/ksh93/bltins/whence.c: whence():
- Refactor and separate the code for reporting functions and
  built-in commands so that both can be reported for one name.

src/cmd/ksh93/data/builtins.c: sh_optwhence[]:
- Correct 'whence --man' to document that:
  * 'type' is equivalent to 'whence -v'
  * '-a' output is like '-v'

src/cmd/ksh93/tests/builtins.sh:
- Test 'whence -a' with these combinations:
  * a function, built-in and external command
  * an undefined/autoload function, built-in and external command

Fixes https://github.com/ksh93/ksh/issues/83

NEWS

@@ -3,6 +3,11 @@ For full details, see the git log at: https://github.com/ksh93/ksh
 
 Any uppercase BUG_* names are modernish shell bug IDs.
 
+2020-07-20:
+
+- If a shell function and a built-in command by the same name exist,
+  'whence -a' and 'type -a' now report both.
+
 2020-07-19:
 
 - Fixed a crash that occured in the '.' command when using kshdb.

src/cmd/ksh93/bltins/whence.c

@@ -138,7 +138,6 @@ static int whence(Shell_t *shp,char **argv, register int flags)
 	register int aflag,r=0;
 	register const char *msg;
 	int	tofree;
-	Dt_t *root;
 	Namval_t *nq;
 	char *notused;
 	Pathcomp_t *pp=0;
@@ -181,32 +180,36 @@ static int whence(Shell_t *shp,char **argv, register int flags)
 		}
 		/* built-ins and functions next */
 	bltins:
-		root = (flags&F_FLAG)?shp->bltin_tree:shp->fun_tree;
+		if(!(flags&F_FLAG) && (np = nv_bfsearch(name, shp->fun_tree, &nq, &notused)) && !is_abuiltin(np))
-		if(np= nv_bfsearch(name, root, &nq, &notused))
 		{
-			if(is_abuiltin(np) && nv_isnull(np))
-				goto search;
-			cp = "";
 			if(flags&V_FLAG)
-			{
 				if(nv_isnull(np))
 					cp = sh_translate(is_ufunction);
-				else if(is_abuiltin(np))
-				{
-					if(nv_isattr(np,BLT_SPC))
-						cp = sh_translate(is_spcbuiltin);
-					else
-						cp = sh_translate(is_builtin);
-				}
 				else
 					cp = sh_translate(is_function);
-			}
+			else
+				cp = "";
+			if(flags&Q_FLAG)
+				continue;
+			sfprintf(sfstdout,"%s%s\n",name,cp);
+			if(!aflag)
+				continue;
+			aflag++;
+		}
+		if((np = nv_bfsearch(name, shp->bltin_tree, &nq, &notused)) && !nv_isnull(np))
+		{
+			if(flags&V_FLAG)
+				if(nv_isattr(np,BLT_SPC))
+					cp = sh_translate(is_spcbuiltin);
+				else
+					cp = sh_translate(is_builtin);
+			else
+				cp = "";
 			if(flags&Q_FLAG)
 				continue;
 			sfprintf(sfstdout,"%s%s\n",name,cp);
 			if(!aflag)
 				continue;
-			cp = 0;
 			aflag++;
 		}
 	search:

src/cmd/ksh93/data/builtins.c

@@ -2017,9 +2017,9 @@ _JOB_
 ;
 
 const char sh_optwhence[] =
-"[-1c?\n@(#)$Id: whence (AT&T Research) 2007-04-24 $\n]"
+"[-1c?\n@(#)$Id: whence (AT&T Research/ksh93) 2020-07-20 $\n]"
 USAGE_LICENSE
-"[+NAME?whence - locate a command and describe its type]"
+"[+NAME?whence, type - locate a command and describe its type]"
 "[+DESCRIPTION?Without \b-v\b, \bwhence\b writes on standard output an "
 	"absolute pathname, if any, corresponding to \aname\a based "
 	"on the complete search order that the shell uses.  If \aname\a "  
@@ -2027,7 +2027,8 @@ USAGE_LICENSE
 "[+?If \b-v\b is specified, the output will also contain information "
 	"that indicates how the given \aname\a would be interpreted by "
 	"the shell in the current execution environment.]" 
-"[a?Displays all uses for each \aname\a rather than the first.]"
+"[+?The \btype\b command is equivalent to \bwhence -v\b.]"
+"[a?Like \b-v\b but displays all uses for each \aname\a rather than the first.]"
 "[f?Do not check for functions.]"
 "[p?Do not check to see if \aname\a is a reserved word, a built-in, "
 	"an alias, or a function.  This turns off the \b-v\b option.]"

src/cmd/ksh93/include/version.h

@@ -17,4 +17,4 @@
 *                  David Korn <dgk@research.att.com>                   *
 *                                                                      *
 ***********************************************************************/
-#define SH_RELEASE	"93u+m 2020-07-19"
+#define SH_RELEASE	"93u+m 2020-07-20"

src/cmd/ksh93/tests/builtins.sh

@@ -753,6 +753,22 @@ $(whence -a -p printf | sed 's/^/printf is /')"
 [[ $actual == $expected ]] || err_exit "'whence -a': incorrect output" \
 	"(expected $(printf %q "$expected"), got $(printf %q "$actual"))"
 
+# 'whence -a'/'type -a' failed to list builtin if function exists: https://github.com/ksh93/ksh/issues/83
+actual=$(printf() { :; }; whence -a printf)
+expected="printf is a function
+printf is a shell builtin
+$(whence -a -p printf | sed 's/^/printf is /')"
+[[ $actual == $expected ]] || err_exit "'whence -a': incorrect output for function+builtin" \
+        "(expected $(printf %q "$expected"), got $(printf %q "$actual"))"
+
+# 'whence -a'/'type -a' failed to list builtin if autoload function exists: https://github.com/ksh93/ksh/issues/83
+actual=$(autoload printf; whence -a printf)
+expected="printf is an undefined function
+printf is a shell builtin
+$(whence -a -p printf | sed 's/^/printf is /')"
+[[ $actual == $expected ]] || err_exit "'whence -a': incorrect output for autoload+builtin" \
+        "(expected $(printf %q "$expected"), got $(printf %q "$actual"))"
+
 # ======
 # 'cd ../.foo' should not exclude the '.' in '.foo'
 (