Merge pull request #13110 from NixOS/mergify/bp/2.28-maintenance/pr-13109

libutil: amend OSC 8 escape stripping for xterm-style separator (backport #13109)

src/libutil-tests/terminal.cc

@@ -66,4 +66,12 @@ TEST(filterANSIEscapes, osc8)
     ASSERT_EQ(filterANSIEscapes("\e]8;;http://example.com\e\\This is a link\e]8;;\e\\"), "This is a link");
 }
 
+TEST(filterANSIEscapes, osc8_bell_as_sep)
+{
+    // gcc-14 uses \a as a separator, xterm style:
+    //   https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
+    ASSERT_EQ(filterANSIEscapes("\e]8;;http://example.com\aThis is a link\e]8;;\a"), "This is a link");
+    ASSERT_EQ(filterANSIEscapes("\e]8;;http://example.com\a\\This is a link\e]8;;\a"), "\\This is a link");
+}
+
 } // namespace nix

src/libutil/terminal.cc

@@ -95,10 +95,19 @@ std::string filterANSIEscapes(std::string_view s, bool filterAll, unsigned int w
             } else if (i != s.end() && *i == ']') {
                 // OSC
                 e += *i++;
-                // eat ESC
+                // https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda defines
-                while (i != s.end() && *i != '\e') e += *i++;
+                // two forms of a URI separator:
-                // eat backslash
+                // 1. ESC '\' (standard)
-                if (i != s.end() && *i == '\\') e += last = *i++;
+                // 2. BEL ('\a') (xterm-style, used by gcc)
+
+                // eat ESC or BEL
+                while (i != s.end() && *i != '\e' && *i != '\a') e += *i++;
+                if (i != s.end()) {
+                  char v = *i;
+                  e += *i++;
+                  // eat backslash after ESC
+                  if (i != s.end() && v == '\e' && *i == '\\') e += last = *i++;
+                }
             } else {
                 if (i != s.end() && *i >= 0x40 && *i <= 0x5f) e += *i++;
             }