Fix vi mode tab completion with spaces (#413)

Attempting to complete file names in vi mode using tab completion can
fail if the last character on the command line is a space. Reproducer
(note that this bug doesn't occur in emacs mode):
   $ set -o vi
   $ mkdir '/tmp/foo bar'
   $ test -d /tmp/foo\ <Tab>

src/cmd/ksh93/edit/vi.c:
- Don't disable tab completion or reset the tab count just because the
  last character on the command line is a space. This bugfix was
  backported from ksh93v- 2014-06-06.

src/cmd/ksh93/tests/pty.sh:
- Add a regression test for the tab completion bug.

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.
 
+2022-01-04:
+
+- Fixed an issue in vi mode that caused tab completion to fail if the
+  last character on the command line was a space.
+
 2021-12-29:
 
 - Fixed numerous build errors that prevented ksh from running on Haiku OS.

src/cmd/ksh93/edit/vi.c

@@ -1528,7 +1528,6 @@ static void getline(register Vi_t* vp,register int mode)
 			if(sh_isoption(SH_VI) &&
 				mode != SEARCH &&
 				last_virt >= 0 &&
-				(vp->ed->e_tabcount || !isblank(cur_virt)) &&
 				sh.nextprompt)
 			{
 				if(virtual[cur_virt]=='\\')
@@ -2479,7 +2478,7 @@ addin:
 			--cur_virt;
 			--last_virt;
 			vp->ocur_virt = MAXCHAR;
-			if(c=='=' || (mode<cur_virt && (virtual[cur_virt]==' ' || virtual[cur_virt]=='/')))
+			if(c=='=' || (mode<cur_virt && virtual[cur_virt]=='/'))
 				vp->ed->e_tabcount = 0;
 			return(APPEND);
 		}

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	"2021-12-29"	/* must be in this format for $((.sh.version)) */
+#define SH_RELEASE_DATE	"2022-01-04"	/* 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/tests/pty.sh

@@ -946,5 +946,17 @@ u ^OK :child-!: \r\n$
 w exit
 !
 
+touch "$tmp/foo bar"
+((SHOPT_VSH || SHOPT_ESH)) && tst $LINENO <<!
+L tab completion with space in string
+# https://github.com/ksh93/ksh/pull/413
+
+d 15
+p :test-1:
+w echo $tmp/foo\\\\ \\t
+r ^:test-1: echo $tmp/foo\\\\ bar \\r\\n$
+r ^$tmp/foo bar\\r\\n$
+!
+
 # ======
 exit $((Errors<125?Errors:125))