Fix compile loop in 32-bit mode for characters above the Unicode limi…

…t when caseless and ucp are set.

ChangeLog

@@ -174,10 +174,14 @@ undefined behaviour.
 that its end is handled similarly to other recursions. This has altered the
 behaviour of   /|(?0)./endanchored   which was previously not right.
 
-48. Improved the test for looping recursion by checking the last referenced 
-character as well as the current character. This allows some patterns that 
-previously triggered the check to run to completion instead of giving the loop 
-error. 
+48. Improved the test for looping recursion by checking the last referenced
+character as well as the current character. This allows some patterns that
+previously triggered the check to run to completion instead of giving the loop
+error.
+
+49. In 32-bit mode, the compiler looped for the pattern /[\x{ffffffff}]/ when
+PCRE2_CASELESS and PCRE2_UCP (but not PCRE2_UTF) were set. Fixed by not trying
+to look for other cases for characters above the Unicode range.
 
 
 Version 10.42 11-December-2022

src/pcre2_compile.c

@@ -5155,10 +5155,14 @@ unsigned int co;
 
 /* Find the first character that has an other case. If it has multiple other
 cases, return its case offset value. When CASELESS_RESTRICT is set, ignore the
-multi-case entries that begin with ASCII values. */
+multi-case entries that begin with ASCII values. In 32-bit mode, a value
+greater than the Unicode maximum ends the range. */
 
 for (c = *cptr; c <= d; c++)
   {
+#if PCRE2_CODE_UNIT_WIDTH == 32
+  if (c > MAX_UTF_CODE_POINT) return -1;
+#endif
   if ((co = UCD_CASESET(c)) != 0 &&
       (!restricted || PRIV(ucd_caseless_sets)[co] > 127))
     {

testdata/testinput12

@@ -573,4 +573,8 @@
 /\X++/
     a\x{110000}\x{ffffffff}
 
+# This used to loop in 32-bit mode; it will fail in 16-bit mode.
+/[\x{ffffffff}]/caseless,ucp
+    \x{ffffffff}xyz
+
 # End of testinput12

testdata/testoutput12-16

@@ -1823,4 +1823,9 @@ Failed: error 134 at offset 11: character code point value in \x{} or \o{} is to
 ** Truncation will probably give the wrong result.
  0: a\x00\x{ffff}
 
+# This used to loop in 32-bit mode; it will fail in 16-bit mode.
+/[\x{ffffffff}]/caseless,ucp
+Failed: error 134 at offset 12: character code point value in \x{} or \o{} is too large
+    \x{ffffffff}xyz
+
 # End of testinput12

testdata/testoutput12-32

@@ -1817,4 +1817,9 @@ No match
     a\x{110000}\x{ffffffff}
  0: a\x{110000}\x{ffffffff}
 
+# This used to loop in 32-bit mode; it will fail in 16-bit mode.
+/[\x{ffffffff}]/caseless,ucp
+    \x{ffffffff}xyz
+ 0: \x{ffffffff}
+
 # End of testinput12