Add str compat functions and use existing wrappers

Provide strsep and strcasestr implementations and use the existing
wrappers instead of direct calls to these functions.

strsep function is wrapped as mutt_str_sep.

auto.def

@@ -367,6 +367,7 @@ if {1} {
     mkdtemp \
     qsort_s \
     strsep \
+    strcasestr \
     tcgetwinsize \
     utimesnsat \
     vasprintf \

keymap.c

@@ -1364,7 +1364,7 @@ static void *parse_menu(bool *menus, char *s, struct Buffer *err)
   char *marker = menu_names_dup;
   char *menu_name = NULL;
 
-  while ((menu_name = strsep(&marker, ",")))
+  while ((menu_name = mutt_str_sep(&marker, ",")))
   {
     int value = mutt_map_get_value(menu_name, MenuNames);
     if (value == -1)

main.c

@@ -442,7 +442,7 @@ static void log_translation(void)
 {
   const char *header = ""; // Do not merge these two lines
   header = _(header);      // otherwise the .po files will end up badly ordered
-  const char *lang = strcasestr(header, "Language:");
+  const char *lang = mutt_istr_find(header, "Language:");
   int len = 64;
   if (lang)
   {

mutt/string.c

@@ -44,6 +44,62 @@
 #include <sysexits.h>
 #endif
 
+#ifndef HAVE_STRCASESTR
+/**
+ * strcasestr - Find the first occurrence of needle in haystack, ignoring case
+ * @param haystack String to search
+ * @param needle   String to find
+ * @retval ptr Matched string, or NULL on failure
+ */
+static char *strcasestr(const char *haystack, const char *needle)
+{
+  size_t haystackn = strlen(haystack);
+  size_t needlen = strlen(needle);
+
+  const char *p = haystack;
+  while (haystackn >= needlen)
+  {
+    if (strncasecmp(p, needle, needlen) == 0)
+      return (char *) p;
+    p++;
+    haystackn--;
+  }
+  return NULL;
+}
+#endif /* HAVE_STRCASESTR */
+
+#ifndef HAVE_STRSEP
+/**
+ * strsep - Extract a token from a string
+ * @param stringp String to be split up
+ * @param delim   Characters to split stringp at
+ * @retval ptr Next token, or NULL if the no more tokens
+ *
+ * @note The pointer stringp will be moved and NULs inserted into it
+ */
+static char *strsep(char **stringp, const char *delim)
+{
+  if (*stringp == NULL)
+    return NULL;
+
+  char *start = *stringp;
+  for (char *p = *stringp; *p != '\0'; p++)
+  {
+    for (const char *s = delim; *s != '\0'; s++)
+    {
+      if (*p == *s)
+      {
+        *p = '\0';
+        *stringp = p + 1;
+        return start;
+      }
+    }
+  }
+  *stringp = NULL;
+  return start;
+}
+#endif /* HAVE_STRSEP */
+
 /**
  * struct SysExits - Lookup table of error messages
  */
@@ -118,6 +174,19 @@ const char *mutt_str_sysexit(int err_num)
   return NULL;
 }
 
+/**
+ * mutt_str_sep - Find first occurance of any of delim characters in *stringp
+ * @param stringp Pointer to string to search for delim, updated with position of after delim if found else NULL
+ * @param delim   String with characters to search for in *stringp
+ * @retval ptr Input value of *stringp
+ */
+char *mutt_str_sep(char **stringp, const char *delim)
+{
+  if (!stringp || !*stringp || !delim)
+    return NULL;
+  return strsep(stringp, delim);
+}
+
 /**
  * startswith - Check whether a string starts with a prefix
  * @param str String to check

mutt/string2.h

@@ -70,6 +70,7 @@ size_t      mutt_str_lws_rlen(const char *s, size_t n);
 const char *mutt_str_next_word(const char *s);
 void        mutt_str_remove_trailing_ws(char *s);
 char *      mutt_str_replace(char **p, const char *s);
+char *      mutt_str_sep(char **stringp, const char *delim);
 char *      mutt_str_skip_email_wsp(const char *s);
 char *      mutt_str_skip_whitespace(const char *p);
 const char *mutt_str_sysexit(int e);

muttlib.c

@@ -1518,11 +1518,11 @@ int mutt_set_xdg_path(enum XdgType type, struct Buffer *buf)
 {
   const char *xdg_env = mutt_str_getenv(xdg_env_vars[type]);
   char *xdg = xdg_env ? mutt_str_dup(xdg_env) : mutt_str_dup(xdg_defaults[type]);
-  char *x = xdg; /* strsep() changes xdg, so free x instead later */
+  char *x = xdg; /* mutt_str_sep() changes xdg, so free x instead later */
   char *token = NULL;
   int rc = 0;
 
-  while ((token = strsep(&xdg, ":")))
+  while ((token = mutt_str_sep(&xdg, ":")))
   {
     if (mutt_buffer_printf(buf, "%s/%s/neomuttrc", token, PACKAGE) < 0)
       continue;

ncrypt/crypt_gpgme.c

@@ -4425,7 +4425,7 @@ static bool verify_sender(struct Email *e)
             tmp_email += mailbox_length;
             tmp_sender += mailbox_length;
             domainname_match =
-                (strncasecmp(tmp_email, tmp_sender, domainname_length) == 0);
+                (mutt_istrn_cmp(tmp_email, tmp_sender, domainname_length) == 0);
             if (mailbox_match && domainname_match)
               rc = false;
           }

nntp/nntp.c

@@ -210,10 +210,10 @@ static int nntp_capabilities(struct NntpAccountData *adata)
   } while (!mutt_str_equal(".", buf));
   *buf = '\0';
 #ifdef USE_SASL
-  if (adata->authenticators && strcasestr(authinfo, " SASL "))
+  if (adata->authenticators && mutt_istr_find(authinfo, " SASL "))
     mutt_str_copy(buf, adata->authenticators, sizeof(buf));
 #endif
-  if (strcasestr(authinfo, " USER "))
+  if (mutt_istr_find(authinfo, " USER "))
   {
     if (*buf != '\0')
       mutt_str_cat(buf, sizeof(buf), " ");
@@ -482,11 +482,9 @@ static int nntp_auth(struct NntpAccountData *adata)
       /* check authenticator */
       if (adata->hasCAPABILITIES)
       {
-        char *m = NULL;
-
         if (!adata->authenticators)
           continue;
-        m = strcasestr(adata->authenticators, method);
+        const char *m = mutt_istr_find(adata->authenticators, method);
         if (!m)
           continue;
         if ((m > adata->authenticators) && (*(m - 1) != ' '))

pattern/exec.c

@@ -73,7 +73,7 @@ static bool patmatch(const struct Pattern *pat, const char *buf)
   if (pat->is_multi)
     return (mutt_list_find(&pat->p.multi_cases, buf) != NULL);
   if (pat->string_match)
-    return pat->ign_case ? strcasestr(buf, pat->p.str) : strstr(buf, pat->p.str);
+    return pat->ign_case ? mutt_istr_find(buf, pat->p.str) : strstr(buf, pat->p.str);
   if (pat->group_match)
     return mutt_group_match(pat->p.group, buf);
   return (regexec(pat->p.regex, buf, 0, NULL, 0) == 0);

rfc3676.c

@@ -245,7 +245,7 @@ static void print_flowed_line(char *line, struct State *s, int ql,
   mutt_debug(LL_DEBUG5, "f=f: line [%s], width = %ld, spaces = %lu\n", line,
              (long) width, fst->spaces);
 
-  for (words = 0; (p = strsep(&line, " "));)
+  for (words = 0; (p = mutt_str_sep(&line, " "));)
   {
     mutt_debug(LL_DEBUG5, "f=f: word [%s], width: %lu, remaining = [%s]\n", p,
                fst->width, line);

test/parse/mutt_parse_mailto.c

@@ -50,7 +50,7 @@ static void check_addrlist(struct AddressList *list, const char *const exp[], si
   char *pp = parsed;
   for (size_t i = 0; i < num; ++i)
   {
-    char *tok = mutt_str_skip_whitespace(strsep(&pp, ","));
+    char *tok = mutt_str_skip_whitespace(mutt_str_sep(&pp, ","));
     if (!TEST_CHECK(mutt_str_equal(tok, exp[i])))
     {
       TEST_MSG("Expected: %s", exp[i]);