Add http_strcasecmp(3)HEADmaster

POSIX.1-2008 does not any locale-specific version of strcasecmp(3), so
conversions to lowercase depend on the system locale.

Since HTTP header fields must be checked without case sensitivity and
not depend on the system locale, a specialised function that forces the
"POSIX" locale is required.

1 files changed, 26 insertions, 0 deletions

diff --git a/http.c b/http.c
index c3c36b2..451ec88 100644
--- a/http.c
+++ b/http.c
@@ -2975,6 +2975,32 @@ end:
     return ret;
 }
 
+int http_strcasecmp(const char *s1, const char *s2)
+{
+    int ret = -1;
+    const locale_t l = newlocale(LC_CTYPE_MASK, "POSIX", (locale_t)0);
+
+    if (l == (locale_t)0)
+    {
+        fprintf(stderr, "%s: newlocale(3): %s\n", __func__, strerror(errno));
+        goto end;
+    }
+
+    while (*s1 && *s2)
+        if (tolower_l(*s1++, l) != tolower_l(*s2++, l))
+        {
+            ret = 1;
+            goto end;
+        }
+
+    ret = !!*s1 || !!*s2;
+end:
+    if (l != (locale_t)0)
+        freelocale(l);
+
+    return ret;
+}
+
 int http_strncasecmp(const char *s1, const char *s2, const size_t n)
 {
     int ret = -1;