Fix caseless minimizing back reference bug when heap in use for recursion.

ChangeLog

@@ -211,6 +211,13 @@ dereference).
 33. If the starting offset was specified as greater than the subject length in 
 a call to pcre2_substitute() an out-of-bounds memory reference could occur.
 
+34. When PCRE2 was compiled to use the heap instead of the stack for recursive 
+calls to match(), a repeated minimizing caseless back reference, or a 
+maximizing one where the two cases had different numbers of code units, 
+followed by a caseful back reference, could lose the caselessness of the first 
+repeated back reference (example: /(Z)(a)\2{1,2}?(?-i)\1X/i should match ZaAAZX 
+but didn't).
+
 
 Version 10.22 29-July-2016
 --------------------------

src/pcre2_match.c

@@ -586,7 +586,6 @@ uint32_t c;       /* Character values not kept over RMATCH() calls */
 BOOL utf;         /* Local copy of UTF flag for speed */
 
 BOOL minimize, possessive; /* Quantifier options */
-BOOL caseless;
 int condcode;
 
 /* When recursion is not being used, all "local" variables that have to be
@@ -724,6 +723,7 @@ still need to be preserved over recursive calls of match(). These macros define
 the alternative names that are used. */
 
 #define allow_zero      cur_is_word
+#define caseless        cur_is_word
 #define cbegroup        condition
 #define code_offset     codelink
 #define condassert      condition

testdata/testinput1

@@ -5815,4 +5815,7 @@ ef) x/x,mark
 /(?s)(?=.*?)b/
     aabc
 
+/(Z)(a)\2{1,2}?(?-i)\1X/i
+    ZaAAZX
+
 # End of testinput1 

testdata/testoutput1

@@ -9289,4 +9289,10 @@ No match
     aabc
  0: b
 
+/(Z)(a)\2{1,2}?(?-i)\1X/i
+    ZaAAZX
+ 0: ZaAAZX
+ 1: Z
+ 2: a
+
 # End of testinput1