liblsd: fix const-correctness in _parse_single_range()

[hector-cao]

_parse_single_range() accepts a const char *str argument and creates a mutable copy via strdup() into orig. However, it was incorrectly calling strchr() and strtoul() on the original const pointer str rather than on the mutable copy.

This is both a correctness bug and a build failure with modern glibc:

• glibc now provides const-preserving overloads of strchr(), returning const char * when passed a const char *. Assigning this to char *p discards the const qualifier, triggering a compile error with -Werror=discarded-qualifiers.
• The subsequent *p++ = '\0' write through p would modify memory via a pointer originally derived from a const string.

Fix by using orig (the mutable strdup copy) for strchr() and strtoul() calls, which is the correct buffer to mutate.

[garlick]

Good catch!

However, a bunch of CI tests are failing with this change, for example:

$ ./t0002-pluglist.t -v
expecting success: 
	/home/garlick/proj/powerman/t/../src/powerman/test_pluglist -f p493 'foo[1-500]' 'p[1-500]' >find.out &&
	cat >find.exp <<-EOT
	plug=p493 node=foo493
	EOT

ok 1 - pluglist foo[1-500] p[1-500] maps expected host to p493

expecting success: 
	/home/garlick/proj/powerman/t/../src/powerman/test_pluglist 't[1,2,3]' 'p[999-1001]' >map1.out &&
	cat >map1.exp <<-EOT &&
	plug=p1001 node=t3
	plug=p1000 node=t2
	plug=p999 node=t1
	EOT
	test_cmp map1.exp map1.out

--- map1.exp	2026-05-28 14:00:03.993386336 +0000
+++ map1.out	2026-05-28 14:00:03.992179170 +0000
@@ -1,3 +1,3 @@
-plug=p1001 node=t3
-plug=p1000 node=t2
-plug=p999 node=t1
+plug=p00001001 node=t3
+plug=p00001000 node=t2
+plug=p00000999 node=t1
[many more failures]

Ah, this seems to be required on top of your change

@@ -1423,8 +1423,8 @@ static int _parse_single_range(const char *str, struct _range *range)
         seterrno_ret(ERANGE, 0);
     }
 
+    range->width = strlen(orig);
     free(orig);
-    range->width = strlen(str);
     return 1;
 
   error:

[garlick]

The same issue might exist in pdsh so ping @grondo

[garlick]

@hector-cao - let me know if you have time to amend and force push this commit with the proposed addition. If not I can submit a new PR. Thanks.

[hector-cao]

@hector-cao - let me know if you have time to amend and force push this commit with the proposed addition. If not I can submit a new PR. Thanks.

thanks for this speedy feedback, updated

[garlick]

Looking good here so let's merge. Thank you for running this down and for your excellent commit message! Let's merge.

[garlick]

👍