Add test for excessive nesting during encode

2 files changed, 16 insertions, 6 deletions

diff --git a/tests/common.lua b/tests/common.lua
index b8ce01d..63d37c0 100644
--- a/tests/common.lua
+++ b/tests/common.lua
@@ -29,7 +29,7 @@ function is_array(table)
     return max
 end
 
-function serialise_table(value, indent)
+function serialise_table(value, indent, depth)
     local spacing, spacing2, indent2
     if indent then 
         spacing = "\n" .. indent
@@ -38,6 +38,10 @@ function serialise_table(value, indent)
     else
         spacing, spacing2, indent2 = " ", " ", false
     end
+    depth = depth + 1
+    if depth > 50 then
+        return "ERROR: Too many nested tables"
+    end
 
     local max = is_array(value)
 
@@ -49,7 +53,7 @@ function serialise_table(value, indent)
             if comma then
                 table.insert(fragment, "," .. spacing2)
             end
-            table.insert(fragment, serialise_value(value[i], indent2))
+            table.insert(fragment, serialise_value(value[i], indent2, depth))
             comma = true
         end
     elseif max < 0 then
@@ -59,8 +63,8 @@ function serialise_table(value, indent)
                 table.insert(fragment, "," .. spacing2)
             end
             table.insert(fragment, string.format(
-                "[%s] = %s", serialise_value(k, indent2),
-                             serialise_value(v, indent2))
+                "[%s] = %s", serialise_value(k, indent2, depth),
+                             serialise_value(v, indent2, depth))
             )
             comma = true
         end
@@ -70,8 +74,9 @@ function serialise_table(value, indent)
     return table.concat(fragment)
 end
 
-function serialise_value(value, indent)
+function serialise_value(value, indent, depth)
     if indent == nil then indent = "" end
+    if depth == nil then depth = 0 end
 
     if value == cjson.null then
         return "cjson.null"
@@ -81,7 +86,7 @@ function serialise_value(value, indent)
            type(value) == "boolean" then
         return tostring(value)
     elseif type(value) == "table" then
-        return serialise_table(value, indent)
+        return serialise_table(value, indent, depth)
     else
         return "\"<" .. type(value) .. ">\""
     end
diff --git a/tests/test.lua b/tests/test.lua
index 436b20c..10d8989 100755
--- a/tests/test.lua
+++ b/tests/test.lua
@@ -63,6 +63,9 @@ if not utf8_loaded then
 end
 local utf16_escaped = gen_utf16_escaped()
 local nested5 = {{{{{ "nested" }}}}}
+local table_cycle = {}
+local table_cycle2 = { table_cycle }
+table_cycle[1] = table_cycle2
 
 local decode_simple_tests = {
     { json.decode, { '"test string"' }, true, { "test string" } },
@@ -124,6 +127,8 @@ local encode_table_tests = {
 
     { json.encode, { nested5 }, true, { '[ [ [ [ [ "nested" ] ] ] ] ]' } },
     { json.encode, { { nested5 } },
+      false, { "Cannot serialise, excessive nesting (6)" } },
+    { json.encode, { table_cycle },
       false, { "Cannot serialise, excessive nesting (6)" } }
 }