doc: add note about call to "regfree" after call to "string_regcomp" (plugin API reference)

doc/en/weechat_plugin_api.en.adoc

@@ -1334,14 +1334,25 @@ Return value:
 * same return code as function `regcomp` (0 if OK, other value for error,
   see `man regcomp`)
 
+[NOTE]
+Regular expression _preg_ must be cleaned by calling "regfree" after use,
+if the function returned 0 (OK).
+
 C example:
 
 [source,C]
 ----
 regex_t my_regex;
-if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) != 0)
+if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) == 0)
+{
+    /* OK */
+    /* ... */
+    regfree (&my_regex);
+}
+else
 {
     /* error */
+    /* ... */
 }
 ----
 

doc/fr/weechat_plugin_api.fr.adoc

@@ -1355,14 +1355,25 @@ Valeur de retour :
 * même code retour que la fonction `regcomp` (0 si ok, autre valeur pour une
   erreur, voir `man regcomp`)
 
+[NOTE]
+L'expression régulière _preg_ doit être nettoyée par un appel à "regfree" après
+utilisation, si la fonction a retourné 0 (OK).
+
 Exemple en C :
 
 [source,C]
 ----
 regex_t my_regex;
-if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) != 0)
+if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) == 0)
+{
+    /* OK */
+    /* ... */
+    regfree (&my_regex);
+}
+else
 {
     /* erreur */
+    /* ... */
 }
 ----
 

doc/it/weechat_plugin_api.it.adoc

@@ -1400,14 +1400,26 @@ Valore restituito:
 * same return code as function `regcomp` (0 if ok, other value for error,
   see `man regcomp`)
 
+[NOTE]
+// TRANSLATION MISSING
+Regular expression _preg_ must be cleaned by calling "regfree" after use,
+if the function returned 0 (OK).
+
 Esempio in C:
 
 [source,C]
 ----
 regex_t my_regex;
-if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) != 0)
+if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) == 0)
+{
+    /* OK */
+    /* ... */
+    regfree (&my_regex);
+}
+else
 {
     /* error */
+    /* ... */
 }
 ----
 

doc/ja/weechat_plugin_api.ja.adoc

@@ -1344,14 +1344,26 @@ int weechat_string_regcomp (void *preg, const char *regex, int default_flags)
 * `regcomp` 関数と同じ戻り値
   (成功の場合は 0、エラーが起きた場合は 0 以外、`man regcomp` を参照)
 
+[NOTE]
+// TRANSLATION MISSING
+Regular expression _preg_ must be cleaned by calling "regfree" after use,
+if the function returned 0 (OK).
+
 C 言語での使用例:
 
 [source,C]
 ----
 regex_t my_regex;
-if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) != 0)
+if (weechat_string_regcomp (&my_regex, "(?i)test", REG_EXTENDED) == 0)
+{
+    /* OK */
+    /* ... */
+    regfree (&my_regex);
+}
+else
 {
     /* error */
+    /* ... */
 }
 ----
 

src/core/wee-string.c

@@ -1300,6 +1300,8 @@ string_regex_flags (const char *regex, int default_flags, int *flags)
  * Returns:
  *   0: successful compilation
  *   other value: compilation failed
+ *
+ * Note: regex must be freed with regfree after use.
  */
 
 int