Abandon pcre2test test if pattern conversion results in a string that is too long

Author: PhilipHazel

ChangeLog

@@ -82,6 +82,9 @@ other tools that prefer the POSIX compatible unicode definition for \d.
 
 20. Report the bit width of the library in use by pcre2test for usability.
 
+21. A pathological pattern conversion test could result in a string longer than 
+the available input buffer. Cause such a test to fail.
+
 
 Version 10.42 11-December-2022
 ------------------------------

src/pcre2test.c

@@ -5825,10 +5825,27 @@ if (pat_patctl.convert_type != CONVERT_UNSET)
 
   else
     {
+    BOOL toolong;
     PCHARSV(converted_pattern, 0, converted_length, utf, outfile);
     fprintf(outfile, "\n");
-    patlen = converted_length;
-    CONVERT_COPY(pbuffer, converted_pattern, converted_length + 1);
+
+    if (test_mode == PCRE8_MODE)
+      toolong = (converted_length + 1 > pbuffer8_size);
+    else if (test_mode == PCRE16_MODE)
+      toolong = (2*(converted_length + 1) > pbuffer8_size);
+    else  /* 32-bit */
+      toolong = (4*(converted_length + 1) > pbuffer8_size);
+
+    if (toolong)
+      {
+      fprintf(outfile, "** Pattern conversion is too long for the buffer\n");
+      convert_return = PR_SKIP;
+      }
+    else
+      {
+      CONVERT_COPY(pbuffer, converted_pattern, converted_length + 1);
+      patlen = converted_length;
+      }
     }
 
   /* Free the converted pattern. */

testdata/testinput25

@@ -15,4 +15,8 @@
 
 /'>' c4 a3 '<'/hex,utf,convert_length=13
 
+# This expansion creates a string that is too long for the input buffer.
+
+/\[()]{65535}()/expand
+
 # End of testinput25