File 1f36c4fb.patch of Package gnuplot.18253

From 1f36c4fbb3e8e0beb213b4a29ab463e43db9ef42 Mon Sep 17 00:00:00 2001
From: Ethan A Merritt <merritt@u.washington.edu>
Date: Fri, 11 Sep 2020 17:38:55 -0700
Subject: [PATCH] prevent buffer overflow of enhanced text fragment

The generic enhanced text buffering uses a shared buffer with fixed length.
Add a check on the current position before adding each character in an
enhanced text fragment.  Affects terminals
  caca canvas dumb emf gd pc pdf pm tkcanvas x11 win
Does not affect terminals with customized text handling
  qt wxt cairo

Bugs #2310 #2311
---
 src/term.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git src/term.c src/term.c
index 7fd46fa04..70a2a7f25 100644
--- src/term.c
+++ src/term.c
@@ -194,6 +194,7 @@ char *enhanced_cur_text = NULL;
 double enhanced_fontscale = 1.0;
 char enhanced_escape_format[16] = "";
 double enhanced_max_height = 0.0, enhanced_min_height = 0.0;
+#define ENHANCED_TEXT_MAX (&enhanced_text[MAX_LINE_LEN])
 /* flag variable to disable enhanced output of filenames, mainly. */
 TBOOLEAN ignore_enhanced_text = FALSE;
 
@@ -2203,6 +2203,9 @@ test_term()
 void
 do_enh_writec(int c)
 {
+    /* Guard against buffer overflow */
+    if (enhanced_cur_text >= ENHANCED_TEXT_MAX)
+	return;
     /* note: c is meant to hold a char, but is actually an int, for
      * the same reasons applying to putc() and friends */
     *enhanced_cur_text++ = c;
-- 
2.26.2