From 3ab51004dabb6619e5badcb7c36bb0b83a65ecb2 Mon Sep 17 00:00:00 2001
From: Reini Urban <reini.urban@gmail.com>
Date: Sun, 29 Sep 2024 11:34:15 +0200
Subject: [PATCH] escape: fix error: null destination pointer

---
 programs/dwg2SVG.c | 3 ++-
 programs/escape.c  | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/programs/dwg2SVG.c b/programs/dwg2SVG.c
index 6f08eaf1e3..f932a36ced 100644
--- a/programs/dwg2SVG.c
+++ b/programs/dwg2SVG.c
@@ -271,7 +271,8 @@ output_TEXT (Dwg_Object *obj)
           obj->index, transform_X (pt.x), transform_Y (pt.y), fontfamily,
           text->height /* fontsize */, entity_color (obj->tio.entity),
           escaped ? escaped : "");
-  free (escaped);
+  if (escaped)
+    free (escaped);
 }
 
 static void
diff --git a/programs/escape.c b/programs/escape.c
index eeaa8f3938..79ecede180 100644
--- a/programs/escape.c
+++ b/programs/escape.c
@@ -33,6 +33,8 @@ htmlescape (const char *restrict src, const Dwg_Codepage cp)
     return NULL;
   len = strlen (src) + 10;
   d = (char *)calloc (len, 1);
+  if (!d)
+    return NULL;
   s = (unsigned char *)src;
   dest = d;
   end = dest + len;
@@ -93,6 +95,8 @@ htmlescape (const char *restrict src, const Dwg_Codepage cp)
             wc = dwg_codepage_uwc (cp, cc);
             if (wc > 127 || wc < 0x20)
               {
+                if (!d)
+                  return NULL;
                 sprintf (d, "&#x%X;", (unsigned)wc); // 4 + 4
                 d += strlen (d);
               }
@@ -123,6 +127,8 @@ htmlwescape (BITCODE_TU wstr)
     len++;
   len += 16;
   d = dest = (char *)calloc (len, 1);
+  if (!d)
+    return NULL;
 
   while (*wstr)
     {
@@ -174,6 +180,8 @@ htmlwescape (BITCODE_TU wstr)
         default:
           if (*wstr >= 127 || *wstr < 20) // utf8 encodings
             {
+              if (!d)
+                return NULL;
               sprintf (d, "&#x%X;", *wstr);
               d += strlen (d);
               *d = 0;