ash: [VAR] Initialise OPTIND after importing environment

Upstream commit 1:

    Date: Fri, 23 Aug 2013 21:27:42 +1000
    [VAR] Initialise OPTIND after importing environment

    On Sat, Mar 23, 2013 at 01:46:20AM +0000, Chris F.A. Johnson wrote:
    >   According to both the dash man page and the POSIX spec, "When the
    >   shell is invoked, OPTIND is initialized to 1."
    >
    >   However, it actually takes the value of the environment variable
    >   if it exists:
    >
    > $ OPTIND=4 dash -c 'echo "$OPTIND"'
    > 4
    > $ OPTIND=4 bash -c 'echo "$OPTIND"'
    > 1
    > $ OPTIND=4 ksh -c 'echo "$OPTIND"'
    > 1
    > $ OPTIND=4 ksh93 -c 'echo "$OPTIND"'
    > 1

    This patch fixes this by initialising OPTIND after importing the
    environment.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Upstream commit 2:

    Date: Tue, 7 Oct 2014 22:24:42 +0800
    [VAR] Use setvareq to set OPTIND initially

    There is no need to setvarint to set the initial value of OPTIND
    of one.  This patch switchs to setvareq which also lets us avoid
    an unnecessary memory allocation.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 9fd1b55..a7c03bb 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -1919,7 +1919,7 @@
 	{ VSTRFIXED|VTEXTFIXED       , "PS2=> "    , NULL            },
 	{ VSTRFIXED|VTEXTFIXED       , "PS4=+ "    , NULL            },
 #if ENABLE_ASH_GETOPTS
-	{ VSTRFIXED|VTEXTFIXED       , "OPTIND=1"  , getoptsreset    },
+	{ VSTRFIXED|VTEXTFIXED       , defoptindvar, getoptsreset    },
 #endif
 #if ENABLE_ASH_RANDOM_SUPPORT
 	{ VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM", change_random },
@@ -13124,6 +13124,8 @@
 			}
 		}
 
+		setvareq((char*)defoptindvar, VTEXTFIXED);
+
 		setvar0("PPID", utoa(getppid()));
 #if ENABLE_ASH_BASH_COMPAT
 		p = lookupvar("SHLVL");