It was reported that iconv_open mishandles // transliteration specifiers :
The cause is in __gconv_translit_find:
cp = __mempcpy (__stpcpy ((char *) newp->fname, runp->name),
memcpy (cp, ".so", sizeof (".so"));
cp points *after* the NUL terminator, so the memcpy call does not actually append ".so", but copies four bytes starting after the terminating NUL character, not changing the string at all—and writing a single NUL byte after the end of the buffer.
Created glibc tracking bugs for this issue:
Affects: fedora-all [bug 1129745]
*** This bug has been marked as a duplicate of bug 1119128 ***