Add JSON_DISABLE_EOF_CHECK decoding flag

With this flag enabled, the decoder stops after a valid JSON input and
thus allows extra data after it.

Fixes GH-25.

diff --git a/doc/apiref.rst b/doc/apiref.rst
index 6ab7a6f..48ff979 100644 (file)
--- a/doc/apiref.rst
+++ b/doc/apiref.rst
@@ -793,6 +793,15 @@ macros can be ORed together to obtain *flags*.
 
    .. versionadded:: 2.1
 
+``JSON_DISABLE_EOF_CHECK``
+   By default, the decoder expects that its whole input constitutes a
+   valid JSON text, and issues an error if there's extra data after
+   the otherwise valid JSON input. With this flag enabled, the decoder
+   stops after decoding a valid JSON array or object, and thus allows
+   extra data after the JSON text.
+
+   .. versionadded:: 2.1
+
 The following functions perform the actual JSON decoding.
 
 .. function:: json_t *json_loads(const char *input, size_t flags, json_error_t *error)

diff --git a/src/jansson.h b/src/jansson.h
index 9bdbb11..79f7ed5 100644 (file)
--- a/src/jansson.h
+++ b/src/jansson.h
@@ -217,6 +217,7 @@ json_t *json_deep_copy(json_t *value);
 /* decoding */
 
 #define JSON_REJECT_DUPLICATES 0x1
+#define JSON_DISABLE_EOF_CHECK 0x2
 
 json_t *json_loads(const char *input, size_t flags, json_error_t *error);
 json_t *json_loadb(const char *buffer, size_t buflen, size_t flags, json_error_t *error);

diff --git a/src/load.c b/src/load.c
index 3dc8ac0..8a53f13 100644 (file)
--- a/src/load.c
+++ b/src/load.c
@@ -827,11 +827,13 @@ static json_t *parse_json(lex_t *lex, size_t flags, json_error_t *error)
     if(!result)
         return NULL;
 
-    lex_scan(lex, error);
-    if(lex->token != TOKEN_EOF) {
-        error_set(error, lex, "end of file expected");
-        json_decref(result);
-        result = NULL;
+    if(!(flags & JSON_DISABLE_EOF_CHECK)) {
+        lex_scan(lex, error);
+        if(lex->token != TOKEN_EOF) {
+            error_set(error, lex, "end of file expected");
+            json_decref(result);
+            result = NULL;
+        }
     }
 
     return result;

diff --git a/test/suites/api/test_load.c b/test/suites/api/test_load.c
index 83143fb..2a60eb3 100644 (file)
--- a/test/suites/api/test_load.c
+++ b/test/suites/api/test_load.c
@@ -32,10 +32,29 @@ static void reject_duplicates()
     check_error("duplicate object key near '\"foo\"'", "<string>", 1, 16, 16);
 }
 
+static void disable_eof_check()
+{
+    json_error_t error;
+    json_t *json;
+
+    const char *text = "{\"foo\": 1} garbage";
+
+    if(json_loads(text, 0, &error))
+        fail("json_loads did not detect garbage after JSON text");
+    check_error("end of file expected near 'garbage'", "<string>", 1, 18, 18);
+
+    json = json_loads(text, JSON_DISABLE_EOF_CHECK, &error);
+    if(!json)
+        fail("json_loads failed with JSON_DISABLE_EOF_CHECK");
+
+    json_decref(json);
+}
+
 int main()
 {
     file_not_found();
     reject_duplicates();
+    disable_eof_check();
 
     return 0;
 }