From c7da6357ff5e6cdc1756047d06667ce7ddfa6e9f Mon Sep 17 00:00:00 2001
From: Jens Steube <jens.steube@gmail.com>
Date: Thu, 30 Apr 2020 13:29:51 +0200
Subject: [PATCH] suppress some handpicked control characters from being
 printed to console

---
 src/convert.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/convert.c b/src/convert.c
index 3a26d6a28..4c344035f 100644
--- a/src/convert.c
+++ b/src/convert.c
@@ -97,6 +97,30 @@ static bool printable_utf8 (const u8 *buf, const size_t len)
     }
   }
 
+  // another round in order to suppress some handpicked control characters from being printed to console
+  // taken from here: https://utf8-chartable.de/unicode-utf8-table.pl
+  // we could inline with the above loop but this way it's easier to understand
+
+  for (size_t pos = 0; pos < len; pos++)
+  {
+    const u8 c0 = buf[pos + 0];
+
+    if (c0 <= 0x1f) return false;
+    if (c0 == 0x7f) return false;
+
+    const size_t left = len - pos;
+
+    if (left >= 2)
+    {
+      const u8 c1 = buf[pos + 1];
+
+      if (c0 == 0xc2)
+      {
+        if ((c1 >= 0x80) && (c1 <= 0x9f)) return false;
+      }
+    }
+  }
+
   return true;
 }