bugfix: wrong argument for pcre2_match.

Author: zhuizhuhaomeng

src/ngx_stream_lua_regex.c

@@ -695,11 +695,11 @@ ngx_stream_lua_ffi_exec_regex(ngx_stream_lua_regex_t *re, int flags,
     ngx_pool_t  *old_pool;
 
     if (flags & NGX_LUA_RE_MODE_DFA) {
-        ovecsize = 2;
+        ovecsize = 1;
         re->ncaptures = 0;
 
     } else {
-        ovecsize = (re->ncaptures + 1) * 3;
+        ovecsize = re->ncaptures + 1;
     }
 
     old_pool = ngx_stream_lua_pcre_malloc_init(NULL);
@@ -717,7 +717,7 @@ ngx_stream_lua_ffi_exec_regex(ngx_stream_lua_regex_t *re, int flags,
         }
 
         ngx_regex_match_data_size = ovecsize;
-        ngx_regex_match_data = pcre2_match_data_create(ovecsize / 3, NULL);
+        ngx_regex_match_data = pcre2_match_data_create(ovecsize, NULL);
 
         if (ngx_regex_match_data == NULL) {
             rc = PCRE2_ERROR_NOMEMORY;
@@ -762,8 +762,8 @@ ngx_stream_lua_ffi_exec_regex(ngx_stream_lua_regex_t *re, int flags,
                    "n %ui, ovecsize %ui", flags, exec_opts, rc, n, ovecsize);
 #endif
 
-    if (!(flags & NGX_LUA_RE_MODE_DFA) && n > ovecsize / 3) {
-        n = ovecsize / 3;
+    if (n > ovecsize) {
+        n = ovecsize;
     }
 
     for (i = 0; i < n; i++) {
@@ -796,6 +796,21 @@ ngx_stream_lua_ffi_exec_regex(ngx_stream_lua_regex_t *re, int flags,
         re->ncaptures = 0;
 
     } else {
+        /* How pcre_exec() returns captured substrings
+         * The first two-thirds of the vector is used to pass back captured
+         * substrings, each substring using a pair of integers. The remaining
+         * third of the vector is used as workspace by pcre_exec() while
+         * matching capturing subpatterns, and is not available for passing
+         * back information. The number passed in ovecsize should always be a
+         * multiple of three. If it is not, it is rounded down.
+         *
+         * When a match is successful, information about captured substrings is
+         * returned in pairs of integers, starting at the beginning of ovector,
+         * and continuing up to two-thirds of its length at the most. The first
+         * element of each pair is set to the byte offset of the first character
+         * in a substring, and the second is set to the byte offset of the first
+         * character after the end of a substring.
+         */
         ovecsize = (re->ncaptures + 1) * 3;
     }
 

t/048-match-dfa.t

@@ -19,7 +19,7 @@ __DATA__
 === TEST 1: matched with d
 --- stream_server_config
     content_by_lua_block {
-        m = ngx.re.match("hello", "(he|hell)", "d")
+        local m = ngx.re.match("hello", "(he|hell)", "d")
         if m then
             ngx.say(m[0])
         else
@@ -34,7 +34,7 @@ hell
 === TEST 2: matched with d + j
 --- stream_server_config
     content_by_lua_block {
-        m = ngx.re.match("hello", "(he|hell)", "jd")
+        local m = ngx.re.match("hello", "(he|hell)", "jd")
         if m then
             ngx.say(m[0])
         else
@@ -49,7 +49,7 @@ hell
 === TEST 3: not matched with j
 --- stream_server_config
     content_by_lua_block {
-        m = ngx.re.match("world", "(he|hell)", "d")
+        local m = ngx.re.match("world", "(he|hell)", "d")
         if m then
             ngx.say(m[0])
         else
@@ -64,7 +64,7 @@ not matched!
 === TEST 4: matched with do
 --- stream_server_config
     content_by_lua_block {
-        m = ngx.re.match("hello", "he|hell", "do")
+        local m = ngx.re.match("hello", "he|hell", "do")
         if m then
             ngx.say(m[0])
             ngx.say(m[1])
@@ -83,7 +83,7 @@ nil
 === TEST 5: not matched with do
 --- stream_server_config
     content_by_lua_block {
-        m = ngx.re.match("world", "([0-9]+)", "do")
+        local m = ngx.re.match("world", "([0-9]+)", "do")
         if m then
             ngx.say(m[0])
         else
@@ -152,3 +152,26 @@ exec opts: 0
 你
 --- no_error_log
 [error]
+
+
+
+=== TEST 8: matched dfa after nfa
+--- stream_server_config
+    content_by_lua_block {
+        local m1 = ngx.re.match("hello", "(a)(a)(a)")
+        if m1 then
+            ngx.say(m1[0])
+        else
+            ngx.say("not matched!")
+        end
+
+        local m2 = ngx.re.match("world", "w", "d")
+        if m2 then
+            ngx.say(m2[0])
+        else
+            ngx.say("not matched!")
+        end
+    }
+--- stream_response
+not matched!
+w