krb5 commit [krb5-1.8]: Work around lack of isblank() on Solaris 8

[Tom Yu]

https://github.com/krb5/krb5/commit/f2ffc1428bb08be4ca082660eee0e4a23ef035cb
commit f2ffc1428bb08be4ca082660eee0e4a23ef035cb
Author: Tom Yu <tlyu at mit.edu>
Date:   Fri Jun 15 13:53:01 2012 -0400

    Work around lack of isblank() on Solaris 8
    
    (cherry picked from commit 4d75811f329fdf893bd7bd5aff84dcfd37cdab89)
    
    ticket: 7175 (new)
    version_fixed: 1.8.7
    status: resolved

 src/configure.in                            |    2 +-
 src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c |    8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/configure.in b/src/configure.in
index e353065..f6d6f94 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -169,7 +169,7 @@ AC_PROG_AWK
 AC_PROG_LEX
 AC_C_CONST
 AC_HEADER_DIRENT
-AC_CHECK_FUNCS(strdup setvbuf inet_ntoa inet_aton seteuid setresuid setreuid setegid setresgid setregid setsid flock fchmod chmod strftime strptime geteuid setenv unsetenv getenv gmtime_r localtime_r bswap16 bswap64 mkstemp getusershell lstat access getcwd srand48 srand srandom stat strchr strerror strerror_r)
+AC_CHECK_FUNCS(strdup setvbuf inet_ntoa inet_aton seteuid setresuid setreuid setegid setresgid setregid setsid flock fchmod chmod strftime strptime geteuid setenv unsetenv getenv gmtime_r localtime_r bswap16 bswap64 mkstemp getusershell lstat access getcwd srand48 srand srandom stat strchr strerror strerror_r isblank)
 
 AC_CHECK_FUNC(mkstemp,
 [MKSTEMP_ST_OBJ=
diff --git a/src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c b/src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c
index 1966aa9..e3c3a81 100644
--- a/src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c
+++ b/src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c
@@ -40,9 +40,15 @@
 #include <kdb5.h>
 #include <kadm5/admin.h>
 
-#if defined(NEED_ISBLANK_PROTO) && !defined(isblank)
+#if !defined(isblank) && defined(HAVE_ISBLANK)
+#if defined(NEED_ISBLANK_PROTO)
 extern int isblank();
 #endif
+#else /* isblank missing */
+#if !defined(isblank)
+#define isblank isspace
+#endif
+#endif
 
 krb5_error_code
 krb5_ldap_get_db_opt(char *input, char **opt, char **val)