return: fix range warn for sizeof(long)==sizeof(int) (re: b90b8cd)

The integer overflow check was based on 'long' being a wider
integer type than 'int', but on 32-bit Linux (at least), they are
the same, so the expected out-of-range warning and 128 exit status
didn't materialise.

src/cmd/ksh93/bltins/cflow.c: b_return():
- Use intmax_t instead of long.
- Don't bother with the check where sizeof(intmax_t)==sizeof(int)
  (generally ancient systems without 'long long').
- Tweaks for code legibility.

src/cmd/ksh93/bltins/cflow.c

@@ -65,14 +65,17 @@ int	b_return(int n, char *argv[],Shbltin_t *context)
 	argv += opt_info.index;
 	if(*argv)
 	{
-		long l = strtol(*argv, NULL, 10);
+		int r;
+		intmax_t l = strtoll(*argv, NULL, 10);
 		if(do_exit)
 			n = (int)(l & SH_EXITMASK);	/* exit: apply bitmask before conversion to avoid undefined int overflow */
-		else if((long)(n = (int)l) != l)	/* return: convert to int and check for overflow (should be safe enough) */
+		else if(r = (int)l, l != (intmax_t)r)	/* return: convert to int and check for overflow (should be safe enough) */
 		{
 			errormsg(SH_DICT,ERROR_warn(0),"%s: out of range",*argv);
 			n = 128;			/* overflow is undefined, so use a consistent status for this */
 		}
+		else
+			n = r;
 	}
 	else
 	{

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	"2024-01-05"	/* must be in this format for $((.sh.version)) */
+#define SH_RELEASE_DATE	"2024-01-08"	/* 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/tests/return.sh

@@ -247,5 +247,27 @@ foo && err_exit "'exit' within { block; } with redirection does not preserve exi
 foo() { false; (exit); }
 foo && err_exit "'exit' within subshell does not preserve exit status"
 
+# ======
+if	let ".sh.version >= 20211208" && builtin getconf 2>/dev/null
+then	max=$(getconf INT_MAX) min=$(getconf INT_MIN) err=$tmp/stderr
+	exp=': out of range'
+	foo() { return $((max+1)); }
+	foo 2>$err
+	[[ e=$? -eq 128 && $(<$err) == *"$exp" ]] || err_exit 'return fails to warn for INT_MAX+1' \
+		"(expected status 128 and *$(printf %q "$exp"), got status $e and $(printf %q "$(<$err)"))"
+	foo() { return $((min-1)); }
+	foo 2>$err
+	[[ e=$? -eq 128 && $(<$err) == *"$exp" ]] || err_exit 'return fails to warn for INT_MIN-1' \
+		"(expected status 128 and *$(printf %q "$exp"), got status $e and $(printf %q "$(<$err)"))"
+	foo() { return $max; }
+	foo 2>$err
+	[[ e=$? -eq max && -z $got ]] || err_exit 'return fails for INT_MAX' \
+		"(expected status 128 and '', got status $e and $(printf %q "$(<$err)"))"
+	foo() { return $min; }
+	foo 2>$err
+	[[ e=$? -eq min && -z $got ]] || err_exit 'return fails for INT_MIN' \
+		"(expected status 128 and '', got status $e and $(printf %q "$(<$err)"))"
+fi
+
 # ======
 exit $((Errors<125?Errors:125))