Fix divide-by-zero in pcre2test

Fixes #728

Found by YinChen001 <497907957@qq.com>

Author: NWilson

src/pcre2test.c

@@ -7620,7 +7620,7 @@ while ((c = *p++) != 0)
       }
 
     replen = CAST8VAR(q) - start_rep;
-    if (replen > (SIZE_MAX - needlen) / i)
+    if (i > 0 && replen > (SIZE_MAX - needlen) / i)
       {
       fprintf(outfile, "** Expanded content too large\n");
       return PR_OK;

testdata/testinput2

@@ -4559,6 +4559,12 @@
 /(abc)*/
     \[abc]{5}
 
+/(abc)*/
+    \[abc]{1}
+
+/(abc)*/
+    \[abc]{0}
+
 /^/gm
     \n\n\n
 

testdata/testoutput2

@@ -14772,6 +14772,15 @@ No match
  0: abcabcabcabcabc
  1: abc
 
+/(abc)*/
+    \[abc]{1}
+ 0: abc
+ 1: abc
+
+/(abc)*/
+    \[abc]{0}
+** Zero or negative repeat not allowed
+
 /^/gm
     \n\n\n
  0: