Fix overly permissive parsing of syntax names on the command line

3 files changed, 14 insertions, 9 deletions

diff --git a/src/n3.c b/src/n3.c
index 6cb8522e..a3cb93a6 100644
--- a/src/n3.c
+++ b/src/n3.c
@@ -1599,7 +1599,8 @@ tokcmp(SerdReader* const reader,
     return -1;
   }
 
-  return serd_strncasecmp((const char*)node->buf, tok, n);
+  assert(node->buf[node->n_bytes] == '\0');
+  return serd_strcasecmp((const char*)node->buf, tok);
 }
 
 SerdStatus
diff --git a/src/serdi.c b/src/serdi.c
index 2bea9e3a..9d0a8f44 100644
--- a/src/serdi.c
+++ b/src/serdi.c
@@ -44,7 +44,7 @@ static SerdSyntax
 get_syntax(const char* const name)
 {
   for (const Syntax* s = syntaxes; s->name; ++s) {
-    if (!serd_strncasecmp(s->name, name, strlen(name))) {
+    if (!serd_strcasecmp(s->name, name)) {
       return s->syntax;
     }
   }
@@ -59,7 +59,7 @@ guess_syntax(const char* const filename)
   const char* ext = strrchr(filename, '.');
   if (ext) {
     for (const Syntax* s = syntaxes; s->name; ++s) {
-      if (!serd_strncasecmp(s->extension, ext, strlen(ext))) {
+      if (!serd_strcasecmp(s->extension, ext)) {
         return s->syntax;
       }
     }
diff --git a/src/string_utils.h b/src/string_utils.h
index 7770e1eb..4babee63 100644
--- a/src/string_utils.h
+++ b/src/string_utils.h
@@ -101,16 +101,20 @@ serd_to_upper(const char c)
   return (char)((c >= 'a' && c <= 'z') ? c - 32 : c);
 }
 
-static inline int
-serd_strncasecmp(const char* s1, const char* s2, size_t n)
+SERD_PURE_FUNC static inline int
+serd_strcasecmp(const char* s1, const char* s2)
 {
-  for (; n > 0 && *s2; s1++, s2++, --n) {
-    if (serd_to_upper(*s1) != serd_to_upper(*s2)) {
-      return ((*(const uint8_t*)s1 < *(const uint8_t*)s2) ? -1 : +1);
+  while (*s1 && *s2) {
+    const char c1 = serd_to_upper(*s1++);
+    const char c2 = serd_to_upper(*s2++);
+    if (c1 != c2) {
+      return (c1 < c2) ? -1 : +1;
     }
   }
 
-  return 0;
+  const char c1 = serd_to_upper(*s1);
+  const char c2 = serd_to_upper(*s2);
+  return (c1 == c2) ? 0 : (c1 < c2) ? -1 : +1;
 }
 
 static inline uint32_t