(trafficserver) branch 10.1.x updated: HRW: Support \r, \n and \t as ctrl chars in values (#12528) (#12547)

[cmcfarlen]

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cmcfarlen pushed a commit to branch 10.1.x
in repository https://gitbox.apache.org/repos/asf/trafficserver.git


The following commit(s) were added to refs/heads/10.1.x by this push:
     new 2eba109b0a HRW: Support \r, \n and \t as ctrl chars in values (#12528) 
(#12547)
2eba109b0a is described below

commit 2eba109b0a4a3e26567074dfd51b9da844a47bc0
Author: Chris McFarlen <ch...@mcfarlen.us>
AuthorDate: Tue Oct 7 13:37:46 2025 -0400

    HRW: Support \r, \n and \t as ctrl chars in values (#12528) (#12547)
    
    (cherry picked from commit 9d3f93405832f74d6dd6f73a59c9add52ae4774f)
    
    Co-authored-by: Leif Hedstrom <zw...@apache.org>
---
 plugins/header_rewrite/parser.cc | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/plugins/header_rewrite/parser.cc b/plugins/header_rewrite/parser.cc
index 921ec2f83a..7fbe381684 100644
--- a/plugins/header_rewrite/parser.cc
+++ b/plugins/header_rewrite/parser.cc
@@ -23,6 +23,7 @@
 #include <iostream>
 #include <string>
 #include <sstream>
+#include <string_view>
 
 #include "ts/ts.h"
 
@@ -65,12 +66,25 @@ Parser::parse_line(const std::string &original_line)
         extracting_token = false;
       }
     } else if ((state != PARSER_IN_REGEX) && (line[i] == '\\')) {
-      // Escaping
+      // Escaping - convert escape sequences to control characters
       if (!extracting_token) {
         extracting_token = true;
         cur_token_start  = i;
       }
-      line.erase(i, 1);
+      // Check if next character forms an escape sequence we want to convert
+      if (i + 1 < line.size()) {
+        constexpr std::string_view controls{"trn", 3};
+        constexpr char             mapped_ctrls[] = "\t\r\n";
+
+        if (auto pos = controls.find(line[i + 1]); pos != 
std::string_view::npos) {
+          line[i] = mapped_ctrls[pos];
+          line.erase(i + 1, 1);
+        } else {
+          line.erase(i, 1);
+        }
+      } else {
+        line.erase(i, 1); // Backslash at end of line
+      }
     } else if ((state != PARSER_IN_REGEX) && (line[i] == '"')) {
       if ((state != PARSER_IN_QUOTE) && !extracting_token) {
         state            = PARSER_IN_QUOTE;