[perl #123802] Assertion failure with /$0{}/

[perl5.git] / caretx.c

diff --git a/caretx.c b/caretx.c
index 25ca195..5d3318c 100644 (file)
--- a/caretx.c
+++ b/caretx.c
@@ -9,7 +9,13 @@
  */
 
 /*
- *     TODO: Quote
+ *   'I do not know clearly,' said Frodo; 'but the path climbs, I think,
+ * up into the mountains on the northern side of that vale where the old
+ * city stands.  It goes up to a high cleft and so down to -- that which
+ * is beyond.'
+ *   'Do you know the name of that high pass?' said Faramir.
+ *
+ *     [p.691 of _The Lord of the Rings_, IV/xi: "The Forbidden Pool"]
  */
 
 /* This file contains a single function, set_caret_X, to set the $^X
@@ -46,7 +52,6 @@
 
 void
 Perl_set_caret_X(pTHX) {
-    dVAR;
     GV* tmpgv = gv_fetchpvs("\030", GV_ADD|GV_NOTQUAL, SVt_PV); /* $^X */
     if (tmpgv) {
         SV *const caret_x = GvSV(tmpgv);
@@ -94,7 +99,13 @@ Perl_set_caret_X(pTHX) {
         }
 #  elif defined(HAS_PROCSELFEXE)
         char buf[MAXPATHLEN];
-        int len = readlink(PROCSELFEXE_PATH, buf, sizeof(buf) - 1);
+        SSize_t len = readlink(PROCSELFEXE_PATH, buf, sizeof(buf) - 1);
+        /* NOTE: if the length returned by readlink() is sizeof(buf) - 1,
+         * it is impossible to know whether the result was truncated. */
+
+        if (len != -1) {
+            buf[len] = '\0';
+        }
 
         /* On Playstation2 Linux V1.0 (kernel 2.2.1) readlink(/proc/self/exe)
            includes a spurious NUL which will cause $^X to fail in system