From: Po Lu <luangruo@yahoo.com>
Date: Fri, 18 Feb 2022 01:12:48 +0000 (+0800)
Subject: Parse XBM images which use character escapes for hex literals
X-Git-Tag: emacs-29.0.90~2259
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=2236ee40ea78973d9377e845bfd0ee3a58cd4386;p=emacs.git

Parse XBM images which use character escapes for hex literals

* src/image.c (xbm_scan): Implement parsing of hex escapes in
character literals.
---

diff --git a/src/image.c b/src/image.c
index 5c1bf8d7be6..d012fcea6a7 100644
--- a/src/image.c
+++ b/src/image.c
@@ -3681,6 +3681,48 @@ xbm_scan (char **s, char *end, char *sval, int *ival)
       *ival = value;
       return overflow ? XBM_TK_OVERFLOW : XBM_TK_NUMBER;
     }
+  /* Character literal.  XBM images typically contain hex escape
+     sequences and not actual characters, so we only try to handle
+     that here.  */
+  else if (c == '\'')
+    {
+      int value = 0, digit;
+      bool overflow = false;
+
+      if (*s == end)
+	return 0;
+
+      c = *(*s)++;
+
+      if (c != '\\' || *s == end)
+	return 0;
+
+      c = *(*s)++;
+
+      if (c == 'x')
+	{
+	  while (*s < end)
+	    {
+	      c = *(*s)++;
+
+	      if (c == '\'')
+		{
+		  *ival = value;
+		  return overflow ? XBM_TK_OVERFLOW : XBM_TK_NUMBER;
+		}
+
+	      digit = char_hexdigit (c);
+
+	      if (digit < 0)
+		return 0;
+
+	      overflow |= INT_MULTIPLY_WRAPV (value, 16, &value);
+	      value += digit;
+	    }
+
+	  return 0;
+	}
+    }
   else if (c_isalpha (c) || c == '_')
     {
       *sval++ = c;