re-pcre: Allocate match span array of needed size.

re-pcre/re.py

@@ -14,12 +14,19 @@ pcre_compile = pcre.func("p", "pcre_compile", "sipps")
 #            int options, int *ovector, int ovecsize);
 pcre_exec = pcre.func("i", "pcre_exec", "ppsiiipi")
 
+#       int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
+#            int what, void *where);
+pcre_fullinfo = pcre.func("i", "pcre_fullinfo", "ppip")
+
+
 IGNORECASE = I = 1
 MULTILINE = M = 2
 DOTALL = S = 4
 VERBOSE = X = 8
 PCRE_ANCHORED = 0x10
 
+PCRE_INFO_CAPTURECOUNT = 2
+
 
 class PCREMatch:
 
@@ -38,7 +45,10 @@ class PCREPattern:
         self.obj = compiled_ptn
 
     def search(self, s, _flags=0):
-        ov = array.array('i', [0, 0, 0] * 2)
+        buf = bytes(4)
+        pcre_fullinfo(self.obj, None, PCRE_INFO_CAPTURECOUNT, buf)
+        cap_count = int.from_bytes(buf)
+        ov = array.array('i', [0, 0, 0] * (cap_count + 1))
         num = pcre_exec(self.obj, None, s, len(s), 0, _flags, ov, len(ov))
         if num == -1:
             # No match