Make pcre2grep work (using the interpreter) if compiled with JIT support when

the main library does not have it.

ChangeLog

@@ -67,6 +67,11 @@ PCRE2_STATIC_RUNTIME). Fix from David Gaussmann.
 expansion when long lines are encountered. Original patch by Dmitry 
 Cherniachenko.
 
+11. If pcre2grep was compiled with JIT support, but the library was compiled 
+without it (something that neither ./configure nor CMake allow, but it can be
+done by editing config.h), pcre2grep was giving a JIT error. Now it detects
+this situation and does not try to use JIT.
+
 
 Version 10.22 29-July-2016
 --------------------------

NON-AUTOTOOLS-BUILD

@@ -174,7 +174,11 @@ can skip ahead to the CMake section.
 
 (11) If you want to use the pcre2grep command, compile and link
      src/pcre2grep.c; it uses only the basic 8-bit PCRE2 library (it does not
-     need the pcre2posix library).
+     need the pcre2posix library). If you have built the PCRE2 library with JIT
+     support by defining SUPPORT_JIT in src/config.h, you can also define
+     SUPPORT_PCRE2GREP_JIT, which causes pcre2grep to make use of JIT (unless
+     it is run with --no-jit). If you define SUPPORT_PCRE2GREP_JIT without
+     defining SUPPORT_JIT, pcre2grep does not try to make use of JIT.
 
 
 STACK SIZE IN WINDOWS ENVIRONMENTS
@@ -389,4 +393,4 @@ and executable, is in EBCDIC and native z/OS file formats and this is the
 recommended download site.
 
 =============================
-Last Updated: 16 July 2015
+Last Updated: 13 October 2016

src/pcre2grep.c

@@ -3460,6 +3460,16 @@ if (jfriedl_XT != 0 || jfriedl_XR != 0)
   }
 #endif
 
+/* If use_jit is set, check whether JIT is available. If not, do not try
+to use JIT. */
+
+if (use_jit)
+  {
+  uint32_t answer; 
+  (void)pcre2_config(PCRE2_CONFIG_JIT, &answer);
+  if (!answer) use_jit = FALSE; 
+  } 
+
 /* Get memory for the main buffer. */
 
 if (bufthird <= 0)