Issue #13545: Fix platform.libc_version() is the SO version is missing

diff --git a/Lib/platform.py b/Lib/platform.py
index 710f21e706c0134e287d2cf0f5fda2274d0aba28..20f8dc6e7a1bc37c40515048f2a1a16a2b23d56c 100755 (executable)
--- a/Lib/platform.py
+++ b/Lib/platform.py
@@ -183,7 +183,7 @@ def libc_ver(executable=sys.executable,lib='',version='',
         elif so:
             if lib != 'glibc':
                 lib = 'libc'
-                if soversion > version:
+                if soversion and soversion > version:
                     version = soversion
                 if threads and version[-len(threads):] != threads:
                     version = version + threads