php_gdb: Handle NULL in format_zstr

Author: TimWolla

main/debug_gdb_scripts.c

@@ -1631,6 +1631,9 @@ asm(
     ".ascii \"    return ary_type.fields()[0].type.range()[1]+1\\n\"\n"
     ".ascii \"\\n\"\n"
     ".ascii \"def format_zstr(zstr):\\n\"\n"
+    ".ascii \"    if zstr.type.code == gdb.TYPE_CODE_PTR and int(zstr) == 0:\\n\"\n"
+    ".ascii \"        return zstr\\n\"\n"
+    ".ascii \"\\n\"\n"
     ".ascii \"    len = int(zstr['len'])\\n\"\n"
     ".ascii \"    truncated = False\\n\"\n"
     ".ascii \"    if len > 200:\\n\"\n"

scripts/gdb/php_gdb.py

@@ -961,6 +961,9 @@ def array_size(ary_type):
     return ary_type.fields()[0].type.range()[1]+1
 
 def format_zstr(zstr):
+    if zstr.type.code == gdb.TYPE_CODE_PTR and int(zstr) == 0:
+        return zstr
+
     len = int(zstr['len'])
     truncated = False
     if len > 200: