From 84989d3af23c717744b8ddeacd6828bc87e7eda1 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 7 Feb 2018 15:19:10 +0100
Subject: Improve filtering of ANSI escape sequences in build logs

All ANSI sequences except color setting are now filtered out. In
particular, terminal resets (such as from NixOS VM tests) are filtered
out.

Also, fix the completely broken tab character handling.
---
 src/nix/progress-bar.cc | 43 ++++---------------------------------------
 1 file changed, 4 insertions(+), 39 deletions(-)

(limited to 'src/nix/progress-bar.cc')

diff --git a/src/nix/progress-bar.cc b/src/nix/progress-bar.cc
index 252d12c5d37f..e6553c06f4ae 100644
--- a/src/nix/progress-bar.cc
+++ b/src/nix/progress-bar.cc
@@ -23,44 +23,6 @@ static uint64_t getI(const std::vector<Logger::Field> & fields, size_t n)
     return fields[n].i;
 }
 
-/* Truncate a string to 'width' printable characters. ANSI escape
-   sequences are copied but not included in the character count. Also,
-   tabs are expanded to spaces. */
-static std::string ansiTruncate(const std::string & s, int width)
-{
-    if (width <= 0) return s;
-
-    std::string t;
-    size_t w = 0;
-    auto i = s.begin();
-
-    while (w < (size_t) width && i != s.end()) {
-        if (*i == '\e') {
-            t += *i++;
-            if (i != s.end() && *i == '[') {
-                t += *i++;
-                while (i != s.end() && (*i < 0x40 || *i > 0x7e)) {
-                    t += *i++;
-                }
-                if (i != s.end()) t += *i++;
-            }
-        }
-
-        else if (*i == '\t') {
-            t += ' '; w++;
-            while (w < (size_t) width && w & 8) {
-                t += ' '; w++;
-            }
-        }
-
-        else {
-            t += *i++; w++;
-        }
-    }
-
-    return t;
-}
-
 class ProgressBar : public Logger
 {
 private:
@@ -343,7 +305,10 @@ public:
             }
         }
 
-        writeToStderr("\r" + ansiTruncate(line, getWindowSize().second) + "\e[K");
+        auto width = getWindowSize().second;
+        if (width <= 0) std::numeric_limits<decltype(width)>::max();
+
+        writeToStderr("\r" + filterANSIEscapes(line, width) + "\e[K");
     }
 
     std::string getStatus(State & state)
-- 
cgit 1.4.1