Fix segmentation fault when resolving a schema with a missing open brace

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

test/CMakeLists.txt

@@ -43,6 +43,7 @@ add_jsonschema_test_unix(validate/fail_relative_external_ref_missing)
 add_jsonschema_test_unix(validate/fail_resolve_enoent)
 add_jsonschema_test_unix(validate/fail_resolve_directory_with_invalid_json)
 add_jsonschema_test_unix(validate/fail_resolve_invalid_json)
+add_jsonschema_test_unix(validate/fail_resolve_missing_open_brace)
 add_jsonschema_test_unix(validate/fail_schema_directory)
 add_jsonschema_test_unix(validate/fail_schema_enoent)
 add_jsonschema_test_unix(validate/fail_schema_invalid_json)

test/validate/fail_resolve_missing_open_brace.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/schema.json"
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "type": "string"
+}
+EOF
+
+cat << 'EOF' > "$TMP/instance.json"
+"foo"
+EOF
+
+cat << 'EOF' > "$TMP/invalid.json"
+
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "$id": "https://example.com",
+  "type": "string"
+}
+EOF
+
+"$1" validate "$TMP/schema.json" "$TMP/instance.json" \
+  --resolve "$TMP/invalid.json" 2>"$TMP/stderr.txt" \
+  && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+error: Failed to parse the JSON document at line 2 and column 3
+  $(realpath "$TMP")/invalid.json
+EOF
+
+diff "$TMP/stderr.txt" "$TMP/expected.txt"