Fix #2345 - json parsing of arrays of objects

cesanta · Aug 16, 2023 · 58886a9 · 58886a9
1 parent 66e022c
commit 58886a9
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Showing 3 changed files with 30 additions and 10 deletions.
diff --git a/mongoose.c b/mongoose.c
@@ -2596,11 +2596,11 @@ int mg_json_get(struct mg_str json, const char *path, int *toklen) {
           if (i + 1 + n >= len) return MG_JSON_NOT_FOUND;
           if (depth < ed) return MG_JSON_NOT_FOUND;
           if (depth == ed && path[pos - 1] != '.') return MG_JSON_NOT_FOUND;
-          // printf("K %s [%.*s] [%.*s] %d %d %d\n", path, pos, path, n,
-          //  &s[i + 1], n, depth, ed);
-          // NOTE(cpq): in the check sequence below is important.
-          // strncmp() must go first: it fails fast if the remaining length of
-          // the path is smaller than `n`.
+          // printf("K %s [%.*s] [%.*s] %d %d %d %d %d\n", path, pos, path, n,
+          //        &s[i + 1], n, depth, ed, ci, ei);
+          //  NOTE(cpq): in the check sequence below is important.
+          //  strncmp() must go first: it fails fast if the remaining length of
+          //  the path is smaller than `n`.
           if (depth == ed && path[pos - 1] == '.' &&
               strncmp(&s[i + 1], &path[pos], (size_t) n) == 0 &&
               (path[pos + n] == '\0' || path[pos + n] == '.' ||
@@ -2632,6 +2632,10 @@ int mg_json_get(struct mg_str json, const char *path, int *toklen) {
         } else if (c == ',') {
           expecting = (nesting[depth - 1] == '{') ? S_KEY : S_VALUE;
         } else if (c == ']' || c == '}') {
+          if (depth == ed && c == '}' && path[pos - 1] == '.')
+            return MG_JSON_NOT_FOUND;
+          if (depth == ed && c == ']' && path[pos - 1] == ',')
+            return MG_JSON_NOT_FOUND;
           MG_EOO('O');
           if (depth == ed && ei >= 0) ci++;
         } else {

diff --git a/src/json.c b/src/json.c
@@ -166,11 +166,11 @@ int mg_json_get(struct mg_str json, const char *path, int *toklen) {
           if (i + 1 + n >= len) return MG_JSON_NOT_FOUND;
           if (depth < ed) return MG_JSON_NOT_FOUND;
           if (depth == ed && path[pos - 1] != '.') return MG_JSON_NOT_FOUND;
-          // printf("K %s [%.*s] [%.*s] %d %d %d\n", path, pos, path, n,
-          //  &s[i + 1], n, depth, ed);
-          // NOTE(cpq): in the check sequence below is important.
-          // strncmp() must go first: it fails fast if the remaining length of
-          // the path is smaller than `n`.
+          // printf("K %s [%.*s] [%.*s] %d %d %d %d %d\n", path, pos, path, n,
+          //        &s[i + 1], n, depth, ed, ci, ei);
+          //  NOTE(cpq): in the check sequence below is important.
+          //  strncmp() must go first: it fails fast if the remaining length of
+          //  the path is smaller than `n`.
           if (depth == ed && path[pos - 1] == '.' &&
               strncmp(&s[i + 1], &path[pos], (size_t) n) == 0 &&
               (path[pos + n] == '\0' || path[pos + n] == '.' ||
@@ -202,6 +202,10 @@ int mg_json_get(struct mg_str json, const char *path, int *toklen) {
         } else if (c == ',') {
           expecting = (nesting[depth - 1] == '{') ? S_KEY : S_VALUE;
         } else if (c == ']' || c == '}') {
+          if (depth == ed && c == '}' && path[pos - 1] == '.')
+            return MG_JSON_NOT_FOUND;
+          if (depth == ed && c == ']' && path[pos - 1] == ',')
+            return MG_JSON_NOT_FOUND;
           MG_EOO('O');
           if (depth == ed && ei >= 0) ci++;
         } else {

diff --git a/test/unit_test.c b/test/unit_test.c
@@ -2939,6 +2939,18 @@ static void test_json(void) {
   ASSERT(mg_json_get_long(mg_str("[0, 42]"), "$[1]", 0) == 42);
   ASSERT(mg_json_get_long(mg_str("[[], 42]"), "$[1]", 0) == 42);
   ASSERT(mg_json_get_long(mg_str("[{}, 42]"), "$[1]", 0) == 42);
+
+  json = mg_str("[{\"a\":1},{\"a\":2}]");
+  ASSERT(mg_json_get_long(json, "$[0]", -1) == -1);
+  ASSERT(mg_json_get_long(json, "$[0].a", -1) == 1);
+  ASSERT(mg_json_get_long(json, "$[1].a", -1) == 2);
+  ASSERT(mg_json_get_long(json, "$[2].a", -1) == -1);
+
+  json = mg_str("[{\"a1\":1},{\"a\":2}]");
+  ASSERT(mg_json_get_long(json, "$[0]", -1) == -1);
+  ASSERT(mg_json_get_long(json, "$[0].a", -1) == -1);
+  ASSERT(mg_json_get_long(json, "$[1].a", -1) == 2);
+  ASSERT(mg_json_get_long(json, "$[2].a", -1) == -1);
 }
 
 static void resp_rpc(struct mg_rpc_req *r) {