- [gl_cv_func_strcasestr_linear=yes], [gl_cv_func_strcasestr_linear=no],
- [dnl pessimistically assume the worst, since even glibc 2.6.1
- dnl has quadratic complexity in its strcasestr
- gl_cv_func_strcasestr_linear="guessing no"])])
+ [gl_cv_func_strcasestr_linear=yes], [gl_cv_func_strcasestr_linear=no],
+ [dnl Only glibc >= 2.9 is known to have an strcasestr that works in
+ dnl linear time.
+ AC_EGREP_CPP([Lucky GNU user],
+ [
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2)
+ Lucky GNU user
+ #endif
+#endif
+ ],
+ [gl_cv_func_strcasestr_linear=yes],
+ [gl_cv_func_strcasestr_linear="guessing no"])
+ ])
+ ])