ash: [VAR] Move unsetvar functionality into setvareq

Upstream commit:

    Date: Tue, 25 May 2010 20:55:05 +0800
    [VAR] Move unsetvar functionality into setvareq

    This patch moves the unsetvar code into setvareq so that we can
    no have a pathological case of an unset variable hanging around
    unless it has a bit pinning it like VEXPORT.

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

function                                             old     new   delta
setvareq                                             227     303     +76
expmeta                                              517     521      +4
localcmd                                             364     366      +2
unsetcmd                                              96      76     -20
unsetvar                                             129       7    -122
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/2 up/down: 82/-142)           Total: -60 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/ash.c

@@ -2269,11 +2269,22 @@ setvareq(char *s, int flags)
 		if (!(vp->flags & (VTEXTFIXED|VSTACK)))
 			free((char*)vp->var_text);
 
+		if (((flags & (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) | (vp->flags & VSTRFIXED)) == VUNSET) {
+			*vpp = vp->next;
+			free(vp);
+ out_free:
+			if ((flags & (VTEXTFIXED|VSTACK|VNOSAVE)) == VNOSAVE)
+				free(s);
+			return;
+		}
+
 		flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
 	} else {
 		/* variable s is not found */
 		if (flags & VNOSET)
 			return;
+		if ((flags & (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) == VUNSET)
+			goto out_free;
 		vp = ckzalloc(sizeof(*vp));
 		vp->next = *vpp;
 		/*vp->func = NULL; - ckzalloc did it */
@@ -2331,43 +2342,10 @@ setvar0(const char *name, const char *val)
 /*
  * Unset the specified variable.
  */
-static int
+static void
 unsetvar(const char *s)
 {
-	struct var **vpp;
-	struct var *vp;
-	int retval;
-
-	vpp = findvar(hashvar(s), s);
-	vp = *vpp;
-	retval = 2;
-	if (vp) {
-		int flags = vp->flags;
-
-		retval = 1;
-		if (flags & VREADONLY)
-			goto out;
-#if ENABLE_ASH_RANDOM_SUPPORT
-		vp->flags &= ~VDYNAMIC;
-#endif
-		if (flags & VUNSET)
-			goto ok;
-		if ((flags & VSTRFIXED) == 0) {
-			INT_OFF;
-			if ((flags & (VTEXTFIXED|VSTACK)) == 0)
-				free((char*)vp->var_text);
-			*vpp = vp->next;
-			free(vp);
-			INT_ON;
-		} else {
 	setvar0(s, NULL);
-			vp->flags &= ~VEXPORT;
-		}
- ok:
-		retval = 0;
-	}
- out:
-	return retval;
 }
 
 /*
@@ -13218,7 +13196,6 @@ unsetcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 	char **ap;
 	int i;
 	int flag = 0;
-	int ret = 0;
 
 	while ((i = nextopt("vf")) != 0) {
 		flag = i;
@@ -13226,15 +13203,13 @@ unsetcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 
 	for (ap = argptr; *ap; ap++) {
 		if (flag != 'f') {
-			i = unsetvar(*ap);
+			unsetvar(*ap);
-			ret |= i;
-			if (!(i & 2))
 			continue;
 		}
 		if (flag != 'v')
 			unsetfunc(*ap);
 	}
-	return ret & 1;
+	return 0;
 }
 
 static const unsigned char timescmd_str[] ALIGN1 = {

shell/ash_test/ash-vars/readonly0.right

@@ -10,4 +10,4 @@ Fail:2
 ./readonly0.tests: export: line 27: a: is read only
 Fail:2
 
-Fail:1
+./readonly0.tests: unset: line 44: a: is read only

shell/ash_test/ash-vars/unset.right

@@ -0,0 +1,17 @@
+./unset.tests: unset: line 3: -: bad variable name
+2
+./unset.tests: unset: line 5: illegal option -m
+2
+0
+___
+0 f g
+0 g
+0
+___
+0 f g
+0
+0 f g
+0
+___
+./unset.tests: unset: line 36: VAR_RO: is read only
+2 f g

shell/ash_test/ash-vars/unset.tests

@@ -0,0 +1,40 @@
+# check invalid options are rejected
+# bash: in posix mode, aborts if non-interactive; using subshell to avoid that
+(unset -)
+echo $?
+(unset -m a b c)
+echo $?
+
+# check funky usage
+unset
+echo $?
+
+# check normal usage
+echo ___
+f=f g=g
+echo $? $f $g
+unset f
+echo $? $f $g
+unset g
+echo $? $f $g
+
+echo ___
+f=f g=g
+echo $? $f $g
+unset f g
+echo $? $f $g
+f=f g=g
+echo $? $f $g
+unset -v f g
+echo $? $f $g
+
+# check read only vars
+echo ___
+f=f g=g
+VAR_RO=1
+readonly VAR_RO
+(unset VAR_RO)
+echo $? $f $g
+# not testing "do variables survive error halfway through unset" since unset aborts
+# unset f VAR_RO g
+#echo $? $f $g

shell/hush_test/hush-vars/unset.right

@@ -12,7 +12,7 @@ ___
 0 f g
 0
 ___
-hush: HUSH_VERSION: readonly variable
+hush: VAR_RO: readonly variable
 1 f g
-hush: HUSH_VERSION: readonly variable
+hush: VAR_RO: readonly variable
 1

shell/hush_test/hush-vars/unset.tests

@@ -1,4 +1,5 @@
 # check invalid options are rejected
+# bash: in posix mode, aborts if non-interactive
 unset -
 echo $?
 unset -m a b c
@@ -30,7 +31,9 @@ echo $? $f $g
 # check read only vars
 echo ___
 f=f g=g
-unset HUSH_VERSION
+VAR_RO=1
+readonly VAR_RO
+unset VAR_RO
 echo $? $f $g
-unset f HUSH_VERSION g
+unset f VAR_RO g
 echo $? $f $g