From 41c13c3a989b819a034eb04d58ad57233ce1ea1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fabian=20St=C3=A4ber?= <fabian@fstab.de>
Date: Sun, 2 Jun 2019 00:15:14 +0200
Subject: [PATCH] #58 better error message for Oniguruma's
 "retry-limit-in-match over"

---
 oniguruma/oniguruma.go       |  3 +++
 oniguruma/oniguruma_helper.c | 21 +++++++++++++++++++--
 oniguruma/oniguruma_helper.h |  1 +
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/oniguruma/oniguruma.go b/oniguruma/oniguruma.go
index 6ccc1016..7abdb15a 100644
--- a/oniguruma/oniguruma.go
+++ b/oniguruma/oniguruma.go
@@ -124,6 +124,9 @@ func (regex *Regex) searchWithOffset(input string, offset int) (*SearchResult, e
 		}, nil
 	} else if r < 0 {
 		C.onig_region_free(region, 1)
+		if C.oniguruma_helper_is_retry_limit_error(r) != 0 {
+			return nil, fmt.Errorf("the match takes too long to process: the oniguruma regular expression library aborted the match with error: %v", errMsg(r))
+		}
 		return nil, errors.New(errMsg(r))
 	} else {
 		return &SearchResult{
diff --git a/oniguruma/oniguruma_helper.c b/oniguruma/oniguruma_helper.c
index ba7e0f10..512ada65 100644
--- a/oniguruma/oniguruma_helper.c
+++ b/oniguruma/oniguruma_helper.c
@@ -18,8 +18,17 @@
 // This initialization wrapper is to be compatible with both, Onituruma 5.9.6 and Oniguruma 6.0.0.
 
 int oniguruma_helper_initialize(OnigEncoding encodings[], int n) {
-    #if ONIGURUMA_VERSION_MAJOR == 6
-        return onig_initialize(encodings, n);
+    #if ONIGURUMA_VERSION_MAJOR >= 6
+        int result = onig_initialize(encodings, n);
+        #if ONIGURUMA_VERSION_MINOR >= 8 && ONIGURUMA_VERSION_TEENY >= 2
+            // In order to avoid retry limit errors in the examples attached to issue #58
+            // we would need to increase the limit by a factor of 100. However, this results
+            // in unreasonably long processing times for the affected match.
+            // As a trade-off, we increase the default by a factor of 10.
+            // See here for documentation: https://github.com/kkos/oniguruma/issues/143
+            onig_set_retry_limit_in_match(10L*onig_get_retry_limit_in_match());
+        #endif
+        return result;
     #else
         return 0;
     #endif
@@ -35,3 +44,11 @@ int oniguruma_helper_error_code_with_info_to_str(UChar* err_buf, int err_code, O
 int oniguruma_helper_error_code_to_str(UChar* err_buf, int err_code) {
     return onig_error_code_to_str(err_buf, err_code);
 }
+
+int oniguruma_helper_is_retry_limit_error(int err_code) {
+    #ifdef ONIGERR_RETRY_LIMIT_IN_MATCH_OVER
+        return err_code == ONIGERR_RETRY_LIMIT_IN_MATCH_OVER;
+    #else
+        return 0;
+    #endif
+}
\ No newline at end of file
diff --git a/oniguruma/oniguruma_helper.h b/oniguruma/oniguruma_helper.h
index 9ddc532d..6c33cbdd 100644
--- a/oniguruma/oniguruma_helper.h
+++ b/oniguruma/oniguruma_helper.h
@@ -17,3 +17,4 @@
 extern int oniguruma_helper_initialize(OnigEncoding encodings[], int n);
 extern int oniguruma_helper_error_code_with_info_to_str(UChar* err_buf, int err_code, OnigErrorInfo *errInfo);
 extern int oniguruma_helper_error_code_to_str(UChar* err_buf, int err_code);
+extern int oniguruma_helper_is_retry_limit_error(int err_code);