From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Graham Inggs <ginggs@ubuntu.com>
Date: May, 17 2026 15:48:54 -0700
Subject: [PATCH] cal: Fix missing ANSI terminal colors due to undefined sprintf in setcolor()

Description: Fix terminal color execution by resolving undefined behavior in sprintf
 Modern compilers optimize out overlapping source/destination pointers in
 sprintf inside setcolor(), causing the ANSI escape prefix (\033[) to drop
 entirely from stdout. This patch writes components directly to stdout.
Author: David Brown <n2rjt@yahoo.com>
Bug: https://salsa.debian.org/salvage-team/cal/-/issues

Bug-Ubuntu: https://bugs.launchpad.net/bugs/2132257
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--- cal-4.1.orig/src/cal.c
+++ cal-4.1/src/cal.c
@@ -1232,7 +1232,6 @@ void ansiputs(char *l, char *a)
  *=========================================================================*/
 void setcolor(char attr)
 {
-    char command[256];
     char dos2ansi[] = { 0, 4, 2, 6, 1, 5, 3, 7, 0, 4, 2, 6, 1, 5, 3, 7};
     if (!crt) return;
 
@@ -1245,12 +1244,10 @@ void setcolor(char attr)
     if (attr == 0)
         fputs("\033[0m",stdout);
     else {
-        strcpy(command,"\033[0;");
-        if (attr&0x80) strcat(command,"5;");
-        if (attr&0x08) strcat(command,"1;");
-        sprintf(command,"%s3%d;4%dm",command,dos2ansi[attr&0x0F],
-                dos2ansi[(attr&0x70)>>4]);
-        fputs(command,stdout);
+        fputs("\033[0;", stdout);
+        if (attr&0x80) fputs("5;", stdout);
+        if (attr&0x08) fputs("1;", stdout);
+        fprintf(stdout, "3%d;4%dm", dos2ansi[attr&0x0F], dos2ansi[(attr&0x70)>>4]);
     }
 }
 #endif /* USE_ANSI */