Fix #77094: Add flags support for pcre_replace_callback(_array)

diff --git a/NEWS b/NEWS
index 30b4103b31b3d7cd3f684a3ef3105a1d283977b9..00a77993e4d9a9879cd08b77245050cf24e2c6ff 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -64,6 +64,7 @@ PHP                                                                        NEWS
 - PCRE:
   . Fixed bug #72685 (Repeated UTF-8 validation of same string in UTF-8 mode).
     (Nikita)
+  . Implemented FR #77094 (Support flags in preg_replace_callback). (Nikita)
 
 - PDO_OCI:
   . Support Oracle Database tracing attributes ACTION, MODULE,

diff --git a/UPGRADING b/UPGRADING
index 49c459e191aeb4c71611a374538dc02c5851b99a..6934c767a147d5bfe6cbfd9339b3781446a9180a 100644 (file)
--- a/UPGRADING
+++ b/UPGRADING
@@ -133,6 +133,12 @@ PHP 7.4 UPGRADE NOTES
   . Support for preloading code has been added.
     RFC: https://wiki.php.net/rfc/preload
 
+- PCRE:
+  . The preg_replace_callback() and preg_replace_callback_array() functions now
+    accept an additional $flags argument, with support for the
+    PREG_OFFSET_CAPTURE and PREG_UNMATCHED_AS_NULL flags. This influences the
+    format of the matches array passed to to the callback function.
+
 - PDO_OCI:
   . PDOStatement::getColumnMeta() is now available
 

diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c
index e1c46842b9d399c1f98003639829f6866427b5ce..ae10f1508bd43196718709fab99c854386e9c5bf 100644 (file)
--- a/ext/pcre/php_pcre.c
+++ b/ext/pcre/php_pcre.c
@@ -956,6 +956,72 @@ static inline void add_offset_pair(zval *result, char *str, size_t len, PCRE2_SI
 }
 /* }}} */
 
+static void populate_subpat_array(
+               zval *subpats, char *subject, PCRE2_SIZE *offsets, char **subpat_names, int count, const PCRE2_SPTR mark, zend_long flags) {
+       zend_bool offset_capture = (flags & PREG_OFFSET_CAPTURE) != 0;
+       zend_bool unmatched_as_null = (flags & PREG_UNMATCHED_AS_NULL) != 0;
+       int i;
+       if (subpat_names) {
+               if (offset_capture) {
+                       for (i = 0; i < count; i++) {
+                               add_offset_pair(subpats, subject + offsets[i<<1],
+                                                               offsets[(i<<1)+1] - offsets[i<<1],
+                                                               offsets[i<<1], subpat_names[i], unmatched_as_null);
+                       }
+               } else {
+                       for (i = 0; i < count; i++) {
+                               if (subpat_names[i]) {
+                                       if (PCRE2_UNSET == offsets[i<<1]) {
+                                               if (unmatched_as_null) {
+                                                       add_assoc_null(subpats, subpat_names[i]);
+                                               } else {
+                                                       add_assoc_str(subpats, subpat_names[i], ZSTR_EMPTY_ALLOC());
+                                               }
+                                       } else {
+                                               add_assoc_stringl(subpats, subpat_names[i], subject + offsets[i<<1],
+                                                                                 offsets[(i<<1)+1] - offsets[i<<1]);
+                                       }
+                               }
+                               if (PCRE2_UNSET == offsets[i<<1]) {
+                                       if (unmatched_as_null) {
+                                               add_next_index_null(subpats);
+                                       } else {
+                                               add_next_index_str(subpats, ZSTR_EMPTY_ALLOC());
+                                       }
+                               } else {
+                                       add_next_index_stringl(subpats, subject + offsets[i<<1],
+                                                                                  offsets[(i<<1)+1] - offsets[i<<1]);
+                               }
+                       }
+               }
+       } else {
+               if (offset_capture) {
+                       for (i = 0; i < count; i++) {
+                               add_offset_pair(subpats, subject + offsets[i<<1],
+                                                               offsets[(i<<1)+1] - offsets[i<<1],
+                                                               offsets[i<<1], NULL, unmatched_as_null);
+                       }
+               } else {
+                       for (i = 0; i < count; i++) {
+                               if (PCRE2_UNSET == offsets[i<<1]) {
+                                       if (unmatched_as_null) {
+                                               add_next_index_null(subpats);
+                                       } else {
+                                               add_next_index_str(subpats, ZSTR_EMPTY_ALLOC());
+                                       }
+                               } else {
+                                       add_next_index_stringl(subpats, subject + offsets[i<<1],
+                                                                                  offsets[(i<<1)+1] - offsets[i<<1]);
+                               }
+                       }
+               }
+       }
+       /* Add MARK, if available */
+       if (mark) {
+               add_assoc_string_ex(subpats, "MARK", sizeof("MARK") - 1, (char *)mark);
+       }
+}
+
 static void php_do_pcre_match(INTERNAL_FUNCTION_PARAMETERS, int global) /* {{{ */
 {
        /* parameters */
@@ -1188,133 +1254,19 @@ matched:
                                                        }
                                                }
                                        } else {
-                                               /* Allocate the result set array */
+                                               /* Allocate and populate the result set array */
                                                array_init_size(&result_set, count + (mark ? 1 : 0));
-
-                                               /* Add all the subpatterns to it */
-                                               if (subpat_names) {
-                                                       if (offset_capture) {
-                                                               for (i = 0; i < count; i++) {
-                                                                       add_offset_pair(&result_set, subject + offsets[i<<1],
-                                                                                                       offsets[(i<<1)+1] - offsets[i<<1], offsets[i<<1], subpat_names[i], unmatched_as_null);
-                                                               }
-                                                       } else {
-                                                               for (i = 0; i < count; i++) {
-                                                                       if (subpat_names[i]) {
-                                                                               if (PCRE2_UNSET == offsets[i<<1]) {
-                                                                                       if (unmatched_as_null) {
-                                                                                               add_assoc_null(&result_set, subpat_names[i]);
-                                                                                       } else {
-                                                                                               add_assoc_str(&result_set, subpat_names[i], ZSTR_EMPTY_ALLOC());
-                                                                                       }
-                                                                               } else {
-                                                                                       add_assoc_stringl(&result_set, subpat_names[i], subject + offsets[i<<1],
-                                                                                                                         offsets[(i<<1)+1] - offsets[i<<1]);
-                                                                               }
-                                                                       }
-                                                                       if (PCRE2_UNSET == offsets[i<<1]) {
-                                                                               if (unmatched_as_null) {
-                                                                                       add_next_index_null(&result_set);
-                                                                               } else {
-                                                                                       add_next_index_str(&result_set, ZSTR_EMPTY_ALLOC());
-                                                                               }
-                                                                       } else {
-                                                                               add_next_index_stringl(&result_set, subject + offsets[i<<1],
-                                                                                                                          offsets[(i<<1)+1] - offsets[i<<1]);
-                                                                       }
-                                                               }
-                                                       }
-                                               } else {
-                                                       if (offset_capture) {
-                                                               for (i = 0; i < count; i++) {
-                                                                       add_offset_pair(&result_set, subject + offsets[i<<1],
-                                                                                                       offsets[(i<<1)+1] - offsets[i<<1], offsets[i<<1], NULL, unmatched_as_null);
-                                                               }
-                                                       } else {
-                                                               for (i = 0; i < count; i++) {
-                                                                       if (PCRE2_UNSET == offsets[i<<1]) {
-                                                                               if (unmatched_as_null) {
-                                                                                       add_next_index_null(&result_set);
-                                                                               } else {
-                                                                                       add_next_index_str(&result_set, ZSTR_EMPTY_ALLOC());
-                                                                               }
-                                                                       } else {
-                                                                               add_next_index_stringl(&result_set, subject + offsets[i<<1],
-                                                                                                                          offsets[(i<<1)+1] - offsets[i<<1]);
-                                                                       }
-                                                               }
-                                                       }
-                                               }
-                                               /* Add MARK, if available */
                                                mark = pcre2_get_mark(match_data);
-                                               if (mark) {
-                                                       add_assoc_string_ex(&result_set, "MARK", sizeof("MARK") - 1, (char *)mark);
-                                               }
+                                               populate_subpat_array(
+                                                       &result_set, subject, offsets, subpat_names, count, mark, flags);
                                                /* And add it to the output array */
                                                zend_hash_next_index_insert(Z_ARRVAL_P(subpats), &result_set);
                                        }
                                } else {                        /* single pattern matching */
                                        /* For each subpattern, insert it into the subpatterns array. */
-                                       if (subpat_names) {
-                                               if (offset_capture) {
-                                                       for (i = 0; i < count; i++) {
-                                                               add_offset_pair(subpats, subject + offsets[i<<1],
-                                                                                               offsets[(i<<1)+1] - offsets[i<<1],
-                                                                                               offsets[i<<1], subpat_names[i], unmatched_as_null);
-                                                       }
-                                               } else {
-                                                       for (i = 0; i < count; i++) {
-                                                               if (subpat_names[i]) {
-                                                                       if (PCRE2_UNSET == offsets[i<<1]) {
-                                                                               if (unmatched_as_null) {
-                                                                                       add_assoc_null(subpats, subpat_names[i]);
-                                                                               } else {
-                                                                                       add_assoc_str(subpats, subpat_names[i], ZSTR_EMPTY_ALLOC());
-                                                                               }
-                                                                       } else {
-                                                                               add_assoc_stringl(subpats, subpat_names[i], subject + offsets[i<<1],
-                                                                                                                 offsets[(i<<1)+1] - offsets[i<<1]);
-                                                                       }
-                                                               }
-                                                               if (PCRE2_UNSET == offsets[i<<1]) {
-                                                                       if (unmatched_as_null) {
-                                                                               add_next_index_null(subpats);
-                                                                       } else {
-                                                                               add_next_index_str(subpats, ZSTR_EMPTY_ALLOC());
-                                                                       }
-                                                               } else {
-                                                                       add_next_index_stringl(subpats, subject + offsets[i<<1],
-                                                                                                                  offsets[(i<<1)+1] - offsets[i<<1]);
-                                                               }
-                                                       }
-                                               }
-                                       } else {
-                                               if (offset_capture) {
-                                                       for (i = 0; i < count; i++) {
-                                                               add_offset_pair(subpats, subject + offsets[i<<1],
-                                                                                               offsets[(i<<1)+1] - offsets[i<<1],
-                                                                                               offsets[i<<1], NULL, unmatched_as_null);
-                                                       }
-                                               } else {
-                                                       for (i = 0; i < count; i++) {
-                                                               if (PCRE2_UNSET == offsets[i<<1]) {
-                                                                       if (unmatched_as_null) {
-                                                                               add_next_index_null(subpats);
-                                                                       } else {
-                                                                               add_next_index_str(subpats, ZSTR_EMPTY_ALLOC());
-                                                                       }
-                                                               } else {
-                                                                       add_next_index_stringl(subpats, subject + offsets[i<<1],
-                                                                                                                  offsets[(i<<1)+1] - offsets[i<<1]);
-                                                               }
-                                                       }
-                                               }
-                                       }
-                                       /* Add MARK, if available */
                                        mark = pcre2_get_mark(match_data);
-                                       if (mark) {
-                                               add_assoc_string_ex(subpats, "MARK", sizeof("MARK") - 1, (char *)mark);
-                                       }
+                                       populate_subpat_array(
+                                               subpats, subject, offsets, subpat_names, count, mark, flags);
                                        break;
                                }
                        }
@@ -1474,29 +1426,14 @@ static int preg_get_backref(char **str, int *backref)
 
 /* {{{ preg_do_repl_func
  */
-static zend_string *preg_do_repl_func(zend_fcall_info *fci, zend_fcall_info_cache *fcc, char *subject, PCRE2_SIZE *offsets, char **subpat_names, int count, const PCRE2_SPTR mark)
+static zend_string *preg_do_repl_func(zend_fcall_info *fci, zend_fcall_info_cache *fcc, char *subject, PCRE2_SIZE *offsets, char **subpat_names, int count, const PCRE2_SPTR mark, zend_long flags)
 {
        zend_string *result_str;
        zval             retval;                        /* Function return value */
        zval         arg;                               /* Argument to pass to function */
-       int                      i;
 
        array_init_size(&arg, count + (mark ? 1 : 0));
-       if (subpat_names) {
-               for (i = 0; i < count; i++) {
-                       if (subpat_names[i]) {
-                               add_assoc_stringl(&arg, subpat_names[i], &subject[offsets[i<<1]] , offsets[(i<<1)+1] - offsets[i<<1]);
-                       }
-                       add_next_index_stringl(&arg, &subject[offsets[i<<1]], offsets[(i<<1)+1] - offsets[i<<1]);
-               }
-       } else {
-               for (i = 0; i < count; i++) {
-                       add_next_index_stringl(&arg, &subject[offsets[i<<1]], offsets[(i<<1)+1] - offsets[i<<1]);
-               }
-       }
-       if (mark) {
-               add_assoc_string(&arg, "MARK", (char *) mark);
-       }
+       populate_subpat_array(&arg, subject, offsets, subpat_names, count, mark, flags);
 
        fci->retval = &retval;
        fci->param_count = 1;
@@ -1792,7 +1729,7 @@ error:
 /* }}} */
 
 /* {{{ php_pcre_replace_func_impl() */
-static zend_string *php_pcre_replace_func_impl(pcre_cache_entry *pce, zend_string *subject_str, char *subject, size_t subject_len, zend_fcall_info *fci, zend_fcall_info_cache *fcc, size_t limit, size_t *replace_count)
+static zend_string *php_pcre_replace_func_impl(pcre_cache_entry *pce, zend_string *subject_str, char *subject, size_t subject_len, zend_fcall_info *fci, zend_fcall_info_cache *fcc, size_t limit, size_t *replace_count, zend_long flags)
 {
        uint32_t                 options;                       /* Execution options */
        int                              count;                         /* Count of matched subpatterns */
@@ -1895,7 +1832,7 @@ matched:
 
                        /* Use custom function to get replacement string and its length. */
                        eval_result = preg_do_repl_func(fci, fcc, subject, offsets, subpat_names, count,
-                               pcre2_get_mark(match_data));
+                               pcre2_get_mark(match_data), flags);
 
                        ZEND_ASSERT(eval_result);
                        new_len = zend_safe_address_guarded(1, ZSTR_LEN(eval_result), new_len);
@@ -2011,7 +1948,7 @@ error:
 static zend_always_inline zend_string *php_pcre_replace_func(zend_string *regex,
                                                          zend_string *subject_str,
                                                          zend_fcall_info *fci, zend_fcall_info_cache *fcc,
-                                                         size_t limit, size_t *replace_count)
+                                                         size_t limit, size_t *replace_count, zend_long flags)
 {
        pcre_cache_entry        *pce;                       /* Compiled regular expression */
        zend_string                     *result;                        /* Function result */
@@ -2021,8 +1958,9 @@ static zend_always_inline zend_string *php_pcre_replace_func(zend_string *regex,
                return NULL;
        }
        pce->refcount++;
-       result = php_pcre_replace_func_impl(pce, subject_str, ZSTR_VAL(subject_str), ZSTR_LEN(subject_str), fci, fcc,
-               limit, replace_count);
+       result = php_pcre_replace_func_impl(
+               pce, subject_str, ZSTR_VAL(subject_str), ZSTR_LEN(subject_str), fci, fcc,
+               limit, replace_count, flags);
        pce->refcount--;
 
        return result;
@@ -2142,17 +2080,14 @@ static zend_always_inline zend_string *php_replace_in_subject(zval *regex, zval
 
 /* {{{ php_replace_in_subject_func
  */
-static zend_string *php_replace_in_subject_func(zval *regex, zend_fcall_info *fci, zend_fcall_info_cache *fcc, zval *subject, size_t limit, size_t *replace_count)
+static zend_string *php_replace_in_subject_func(zval *regex, zend_fcall_info *fci, zend_fcall_info_cache *fcc, zval *subject, size_t limit, size_t *replace_count, zend_long flags)
 {
        zend_string *result;
        zend_string     *subject_str = zval_get_string(subject);
 
        if (Z_TYPE_P(regex) != IS_ARRAY) {
-               result = php_pcre_replace_func(Z_STR_P(regex),
-                                                                 subject_str,
-                                                                 fci, fcc,
-                                                                 limit,
-                                                                 replace_count);
+               result = php_pcre_replace_func(
+                       Z_STR_P(regex), subject_str, fci, fcc, limit, replace_count, flags);
                zend_string_release_ex(subject_str, 0);
                return result;
        } else {
@@ -2168,11 +2103,8 @@ static zend_string *php_replace_in_subject_func(zval *regex, zend_fcall_info *fc
 
                        /* Do the actual replacement and put the result back into subject_str
                           for further replacements. */
-                       result = php_pcre_replace_func(regex_str,
-                                                                                  subject_str,
-                                                                                  fci, fcc,
-                                                                                  limit,
-                                                                                  replace_count);
+                       result = php_pcre_replace_func(
+                               regex_str, subject_str, fci, fcc, limit, replace_count, flags);
                        zend_tmp_string_release(tmp_regex_str);
                        zend_string_release_ex(subject_str, 0);
                        subject_str = result;
@@ -2188,7 +2120,7 @@ static zend_string *php_replace_in_subject_func(zval *regex, zend_fcall_info *fc
 
 /* {{{ preg_replace_func_impl
  */
-static size_t preg_replace_func_impl(zval *return_value, zval *regex, zend_fcall_info *fci, zend_fcall_info_cache *fcc, zval *subject, zend_long limit_val)
+static size_t preg_replace_func_impl(zval *return_value, zval *regex, zend_fcall_info *fci, zend_fcall_info_cache *fcc, zval *subject, zend_long limit_val, zend_long flags)
 {
        zend_string     *result;
        size_t replace_count = 0;
@@ -2198,7 +2130,8 @@ static size_t preg_replace_func_impl(zval *return_value, zval *regex, zend_fcall
        }
 
        if (Z_TYPE_P(subject) != IS_ARRAY) {
-               result = php_replace_in_subject_func(regex, fci, fcc, subject, limit_val, &replace_count);
+               result = php_replace_in_subject_func(
+                       regex, fci, fcc, subject, limit_val, &replace_count, flags);
                if (result != NULL) {
                        RETVAL_STR(result);
                } else {
@@ -2215,7 +2148,8 @@ static size_t preg_replace_func_impl(zval *return_value, zval *regex, zend_fcall
                /* For each subject entry, convert it to string, then perform replacement
                   and add the result to the return_value array. */
                ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(subject), num_key, string_key, subject_entry) {
-                       result = php_replace_in_subject_func(regex, fci, fcc, subject_entry, limit_val, &replace_count);
+                       result = php_replace_in_subject_func(
+                               regex, fci, fcc, subject_entry, limit_val, &replace_count, flags);
                        if (result != NULL) {
                                /* Add to return array */
                                ZVAL_STR(&zv, result);
@@ -2333,19 +2267,20 @@ static PHP_FUNCTION(preg_replace)
 static PHP_FUNCTION(preg_replace_callback)
 {
        zval *regex, *replace, *subject, *zcount = NULL;
-       zend_long limit = -1;
+       zend_long limit = -1, flags = 0;
        size_t replace_count;
        zend_fcall_info fci;
        zend_fcall_info_cache fcc;
 
        /* Get function parameters and do error-checking. */
-       ZEND_PARSE_PARAMETERS_START(3, 5)
+       ZEND_PARSE_PARAMETERS_START(3, 6)
                Z_PARAM_ZVAL(regex)
                Z_PARAM_ZVAL(replace)
                Z_PARAM_ZVAL(subject)
                Z_PARAM_OPTIONAL
                Z_PARAM_LONG(limit)
                Z_PARAM_ZVAL(zcount)
+               Z_PARAM_LONG(flags)
        ZEND_PARSE_PARAMETERS_END();
 
        if (!zend_is_callable_ex(replace, NULL, 0, NULL, &fcc, NULL)) {
@@ -2360,7 +2295,7 @@ static PHP_FUNCTION(preg_replace_callback)
        fci.object = NULL;
        ZVAL_COPY_VALUE(&fci.function_name, replace);
 
-       replace_count = preg_replace_func_impl(return_value, regex, &fci, &fcc, subject, limit);
+       replace_count = preg_replace_func_impl(return_value, regex, &fci, &fcc, subject, limit, flags);
        if (zcount) {
                ZEND_TRY_ASSIGN_LONG(zcount, replace_count);
        }
@@ -2372,19 +2307,20 @@ static PHP_FUNCTION(preg_replace_callback)
 static PHP_FUNCTION(preg_replace_callback_array)
 {
        zval regex, zv, *replace, *subject, *pattern, *zcount = NULL;
-       zend_long limit = -1;
+       zend_long limit = -1, flags = 0;
        zend_string *str_idx;
        size_t replace_count = 0;
        zend_fcall_info fci;
        zend_fcall_info_cache fcc;
 
        /* Get function parameters and do error-checking. */
-       ZEND_PARSE_PARAMETERS_START(2, 4)
+       ZEND_PARSE_PARAMETERS_START(2, 5)
                Z_PARAM_ARRAY(pattern)
                Z_PARAM_ZVAL(subject)
                Z_PARAM_OPTIONAL
                Z_PARAM_LONG(limit)
                Z_PARAM_ZVAL(zcount)
+               Z_PARAM_LONG(flags)
        ZEND_PARSE_PARAMETERS_END();
 
        fci.size = sizeof(fci);
@@ -2411,7 +2347,7 @@ static PHP_FUNCTION(preg_replace_callback_array)
 
                ZVAL_COPY_VALUE(&fci.function_name, replace);
 
-               replace_count += preg_replace_func_impl(&zv, &regex, &fci, &fcc, subject, limit);
+               replace_count += preg_replace_func_impl(&zv, &regex, &fci, &fcc, subject, limit, flags);
                if (subject != return_value) {
                        subject = return_value;
                } else {
@@ -2958,6 +2894,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_preg_replace_callback, 0, 0, 3)
     ZEND_ARG_INFO(0, subject)
     ZEND_ARG_INFO(0, limit)
     ZEND_ARG_INFO(1, count)
+    ZEND_ARG_INFO(0, flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_preg_replace_callback_array, 0, 0, 2)
@@ -2965,6 +2902,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_preg_replace_callback_array, 0, 0, 2)
     ZEND_ARG_INFO(0, subject)
     ZEND_ARG_INFO(0, limit)
     ZEND_ARG_INFO(1, count)
+    ZEND_ARG_INFO(0, flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_preg_split, 0, 0, 2)

diff --git a/ext/pcre/tests/preg_replace_callback_flags.phpt b/ext/pcre/tests/preg_replace_callback_flags.phpt
new file mode 100644 (file)
index 0000000..f85f9a5
--- /dev/null
+++ b/ext/pcre/tests/preg_replace_callback_flags.phpt
@@ -0,0 +1,126 @@
+--TEST--
+Support for flags in preg_replace_callback(_array)
+--FILE--
+<?php
+
+var_dump(preg_replace_callback('/./', function($matches) {
+    var_dump($matches);
+    return $matches[0][0];
+}, 'abc', -1, $count, PREG_OFFSET_CAPTURE));
+echo "\n";
+
+var_dump(preg_replace_callback_array(
+    ['/./' => function($matches) {
+        var_dump($matches);
+        return $matches[0][0];
+    }],
+    'abc', -1, $count, PREG_OFFSET_CAPTURE)
+);
+echo "\n";
+
+var_dump(preg_replace_callback('/(a)|(b)/', function($matches) {
+    var_dump($matches);
+    return $matches[0];
+}, 'abc', -1, $count, PREG_UNMATCHED_AS_NULL));
+echo "\n";
+
+var_dump(preg_replace_callback_array(
+    ['/(a)|(b)/' => function($matches) {
+        var_dump($matches);
+        return $matches[0];
+    }],
+    'abc', -1, $count, PREG_UNMATCHED_AS_NULL)
+);
+echo "\n";
+
+?>
+--EXPECT--
+array(1) {
+  [0]=>
+  array(2) {
+    [0]=>
+    string(1) "a"
+    [1]=>
+    int(0)
+  }
+}
+array(1) {
+  [0]=>
+  array(2) {
+    [0]=>
+    string(1) "b"
+    [1]=>
+    int(1)
+  }
+}
+array(1) {
+  [0]=>
+  array(2) {
+    [0]=>
+    string(1) "c"
+    [1]=>
+    int(2)
+  }
+}
+string(3) "abc"
+
+array(1) {
+  [0]=>
+  array(2) {
+    [0]=>
+    string(1) "a"
+    [1]=>
+    int(0)
+  }
+}
+array(1) {
+  [0]=>
+  array(2) {
+    [0]=>
+    string(1) "b"
+    [1]=>
+    int(1)
+  }
+}
+array(1) {
+  [0]=>
+  array(2) {
+    [0]=>
+    string(1) "c"
+    [1]=>
+    int(2)
+  }
+}
+string(3) "abc"
+
+array(2) {
+  [0]=>
+  string(1) "a"
+  [1]=>
+  string(1) "a"
+}
+array(3) {
+  [0]=>
+  string(1) "b"
+  [1]=>
+  NULL
+  [2]=>
+  string(1) "b"
+}
+string(3) "abc"
+
+array(2) {
+  [0]=>
+  string(1) "a"
+  [1]=>
+  string(1) "a"
+}
+array(3) {
+  [0]=>
+  string(1) "b"
+  [1]=>
+  NULL
+  [2]=>
+  string(1) "b"
+}
+string(3) "abc"