From 8cc5e5c11d26b2af9acff9898c2b226e2e781e36 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Wed, 3 Sep 2025 20:36:42 +0900
Subject: [PATCH] Win32: Fix fallback parsing of CSI SGR sequences

---
 win32/win32.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/win32/win32.c b/win32/win32.c
index 72539e8a63b209..1a5308337a05d3 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -6793,47 +6793,54 @@ constat_attr(int count, const int *seq, WORD attr, WORD default_attr, int *rever
           case 1:
             bold = FOREGROUND_INTENSITY;
             break;
+          case 22:
+            bold = 0;
+            break;
           case 4:
 #ifndef COMMON_LVB_UNDERSCORE
 #define COMMON_LVB_UNDERSCORE 0x8000
 #endif
             attr |= COMMON_LVB_UNDERSCORE;
             break;
+          case 24:
+            attr &= ~COMMON_LVB_UNDERSCORE;
+            break;
           case 7:
             rev = 1;
             break;
+          case 27:
+            rev = 0;
+            break;
 
           case 30:
             attr &= ~(FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_RED);
             break;
-          case 17:
           case 31:
             attr = (attr & ~(FOREGROUND_BLUE | FOREGROUND_GREEN)) | FOREGROUND_RED;
             break;
-          case 18:
           case 32:
             attr = (attr & ~(FOREGROUND_BLUE | FOREGROUND_RED)) | FOREGROUND_GREEN;
             break;
-          case 19:
           case 33:
             attr = (attr & ~FOREGROUND_BLUE) | FOREGROUND_GREEN | FOREGROUND_RED;
             break;
-          case 20:
           case 34:
             attr = (attr & ~(FOREGROUND_GREEN | FOREGROUND_RED)) | FOREGROUND_BLUE;
             break;
-          case 21:
           case 35:
             attr = (attr & ~FOREGROUND_GREEN) | FOREGROUND_BLUE | FOREGROUND_RED;
             break;
-          case 22:
           case 36:
             attr = (attr & ~FOREGROUND_RED) | FOREGROUND_BLUE | FOREGROUND_GREEN;
             break;
-          case 23:
           case 37:
             attr |= FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_RED;
             break;
+          case 38: /* 256-color or true color; N/A on old Command Prompt */
+            break;
+          case 39:
+            attr = (attr & ~FOREGROUND_MASK) | (default_attr & FOREGROUND_MASK);
+            break;
 
           case 40:
             attr &= ~(BACKGROUND_BLUE | BACKGROUND_GREEN | BACKGROUND_RED);
@@ -6859,6 +6866,11 @@ constat_attr(int count, const int *seq, WORD attr, WORD default_attr, int *rever
           case 47:
             attr |= BACKGROUND_BLUE | BACKGROUND_GREEN | BACKGROUND_RED;
             break;
+          case 48: /* 256-color or true color; N/A on old Command Prompt */
+            break;
+          case 49:
+            attr = (attr & ~BACKGROUND_MASK) | (default_attr & BACKGROUND_MASK);
+            break;
         }
     }
     attr |= bold;