pcre2_compile: make errorcode parameter optional

When the pcre2_compile interface was introduced, code was added to check
that BOTH the errorcode and erroroffset were not NULL, but usually only
one or the other is needed, in adition to a NULL return value to detect
failures.

Make the minimum change possible to allow passing a NULL and simplify
some of the calls used in pcre2_jit_test that will benefit from this
change.

A more complex change that would also avoid the multiple places where
checks for it were added has been punted from this change.

doc/pcre2_compile.3

@@ -21,7 +21,7 @@ arguments are:
   \fIpattern\fP       A string containing expression to be compiled
   \fIlength\fP        The length of the string or PCRE2_ZERO_TERMINATED
   \fIoptions\fP       Option bits
-  \fIerrorcode\fP     Where to put an error code
+  \fIerrorcode\fP     Where to put an error code or NULL
   \fIerroffset\fP     Where to put an error offset
   \fIccontext\fP      Pointer to a compile context or NULL
 .sp

src/pcre2_compile.c

@@ -9812,17 +9812,17 @@ PCRE2_UCHAR *cworkspace = (PCRE2_UCHAR *)c16workspace;
 
 /* -------------- Check arguments and set up the pattern ----------------- */
 
-/* There must be error code and offset pointers. */
+/* There must be an error offset pointer. */
 
-if (errorptr == NULL || erroroffset == NULL) return NULL;
-*errorptr = ERR0;
+if (erroroffset == NULL) return NULL;
+if (errorptr) *errorptr = ERR0;
 *erroroffset = 0;
 
 /* There must be a pattern! */
 
 if (pattern == NULL)
   {
-  *errorptr = ERR16;
+  if (errorptr) *errorptr = ERR16;
   return NULL;
   }
 
@@ -9840,7 +9840,7 @@ if ((options & PCRE2_MATCH_INVALID_UTF) != 0) options |= PCRE2_UTF;
 if ((options & ~PUBLIC_COMPILE_OPTIONS) != 0 ||
     (ccontext->extra_options & ~PUBLIC_COMPILE_EXTRA_OPTIONS) != 0)
   {
-  *errorptr = ERR17;
+  if (errorptr) *errorptr = ERR17;
   return NULL;
   }
 
@@ -9848,7 +9848,7 @@ if ((options & PCRE2_LITERAL) != 0 &&
     ((options & ~PUBLIC_LITERAL_COMPILE_OPTIONS) != 0 ||
      (ccontext->extra_options & ~PUBLIC_LITERAL_COMPILE_EXTRA_OPTIONS) != 0))
   {
-  *errorptr = ERR92;
+  if (errorptr) *errorptr = ERR92;
   return NULL;
   }
 
@@ -9860,7 +9860,7 @@ if ((zero_terminated = (patlen == PCRE2_ZERO_TERMINATED)))
 
 if (patlen > ccontext->max_pattern_length)
   {
-  *errorptr = ERR88;
+  if (errorptr) *errorptr = ERR88;
   return NULL;
   }
 
@@ -10144,7 +10144,7 @@ if (parsed_size_needed >= PARSED_PATTERN_DEFAULT_SIZE)
     (parsed_size_needed + 1) * sizeof(uint32_t), ccontext->memctl.memory_data);
   if (heap_parsed_pattern == NULL)
     {
-    *errorptr = ERR21;
+    if (errorptr) *errorptr = ERR21;
     goto EXIT;
     }
   cb.parsed_pattern = heap_parsed_pattern;
@@ -10614,7 +10614,7 @@ HAD_EARLY_ERROR:
 *erroroffset = ptr - pattern;
 
 HAD_ERROR:
-*errorptr = errorcode;
+if (errorptr) *errorptr = errorcode;
 pcre2_code_free(re);
 re = NULL;
 goto EXIT;

src/pcre2_jit_test.c

@@ -1998,7 +1998,7 @@ static int run_invalid_utf8_test(const struct invalid_utf8_regression_test_case
 	int pattern_index, int i, pcre2_compile_context_8 *ccontext, pcre2_match_data_8 *mdata)
 {
 	pcre2_code_8 *code;
-	int result, errorcode;
+	int result;
 	PCRE2_SIZE length, erroroffset;
 	PCRE2_SIZE *ovector = pcre2_get_ovector_pointer_8(mdata);
 
@@ -2006,7 +2006,7 @@ static int run_invalid_utf8_test(const struct invalid_utf8_regression_test_case
 		return 1;
 
 	code = pcre2_compile_8((PCRE2_UCHAR8*)current->pattern[i], PCRE2_ZERO_TERMINATED,
-		current->compile_options, &errorcode, &erroroffset, ccontext);
+		current->compile_options, NULL, &erroroffset, ccontext);
 
 	if (!code) {
 		printf("Pattern[%d:0] cannot be compiled. Error offset: %d\n", pattern_index, (int)erroroffset);
@@ -2207,7 +2207,7 @@ static int run_invalid_utf16_test(const struct invalid_utf16_regression_test_cas
 	int pattern_index, int i, pcre2_compile_context_16 *ccontext, pcre2_match_data_16 *mdata)
 {
 	pcre2_code_16 *code;
-	int result, errorcode;
+	int result;
 	PCRE2_SIZE length, erroroffset;
 	const PCRE2_UCHAR16 *input;
 	PCRE2_SIZE *ovector = pcre2_get_ovector_pointer_16(mdata);
@@ -2216,7 +2216,7 @@ static int run_invalid_utf16_test(const struct invalid_utf16_regression_test_cas
 		return 1;
 
 	code = pcre2_compile_16(current->pattern[i], PCRE2_ZERO_TERMINATED,
-		current->compile_options, &errorcode, &erroroffset, ccontext);
+		current->compile_options, NULL, &erroroffset, ccontext);
 
 	if (!code) {
 		printf("Pattern[%d:0] cannot be compiled. Error offset: %d\n", pattern_index, (int)erroroffset);
@@ -2394,7 +2394,7 @@ static int run_invalid_utf32_test(const struct invalid_utf32_regression_test_cas
 	int pattern_index, int i, pcre2_compile_context_32 *ccontext, pcre2_match_data_32 *mdata)
 {
 	pcre2_code_32 *code;
-	int result, errorcode;
+	int result;
 	PCRE2_SIZE length, erroroffset;
 	const PCRE2_UCHAR32 *input;
 	PCRE2_SIZE *ovector = pcre2_get_ovector_pointer_32(mdata);
@@ -2403,7 +2403,7 @@ static int run_invalid_utf32_test(const struct invalid_utf32_regression_test_cas
 		return 1;
 
 	code = pcre2_compile_32(current->pattern[i], PCRE2_ZERO_TERMINATED,
-		current->compile_options, &errorcode, &erroroffset, ccontext);
+		current->compile_options, NULL, &erroroffset, ccontext);
 
 	if (!code) {
 		printf("Pattern[%d:0] cannot be compiled. Error offset: %d\n", pattern_index, (int)erroroffset);