ref: 2742165cfb013df15ba69f211678e32209a6c03e
parent: 00f50e30f9b10dfd7920d2744e56c35e6b67a5f4
author: qwx <qwx@sciops.net>
date: Mon Aug 18 12:00:52 EDT 2025
devenv: fix off-by-one in nul to space replacement (thanks cinap_lenrek) e->value may be nul-terminated, which is taken into account by e->len. commit 8f3b47e092eb07e20238089a047f2993242d3302 unintentionally replaced that nul with a space before appending another nul. variables such as $mouseport would have a space character appended to their value and be no longer recognized in scripts like /rc/bin/screenrc. instead, check for any terminating nul characters and skip them.
--- a/sys/src/9/port/devenv.c
+++ b/sys/src/9/port/devenv.c
@@ -504,7 +504,7 @@
Egrp *eg = &confegrp;
Evalue *e;
char *p, *q;
- int i, n;
+ int i, n, m;
rlock(eg);
n = 1;
@@ -528,12 +528,16 @@
memmove(q, e->name, n);
q += n;
memmove(q, e->value, e->len);
- q[e->len] = 0;
- for(n=0; n<e->len; n++){+ for(m = e->len; m > 0; m--){+ if(q[m-1] != '\0')
+ break;
+ }
+ for(n = 0; n < m; n++){if(q[n] == '\0')
q[n] = ' ';
}
- q += n+1;
+ q[m] = 0;
+ q += m+1;
}
*q = '\0';
runlock(eg);
--
⑨