Consolidate lower and upper logic (#2594)

src/curl.cpp

@@ -593,8 +593,7 @@ size_t S3fsCurl::HeaderCallback(void* data, size_t blockSize, size_t numBlocks,
 
     if(getline(ss, key, ':')){
         // Force to lower, only "x-amz"
-        std::string lkey = key;
-        transform(lkey.cbegin(), lkey.cend(), lkey.begin(), static_cast<int (*)(int)>(std::tolower));
+        std::string lkey = lower(key);
         if(is_prefix(lkey.c_str(), "x-amz")){
             key = lkey;
         }
@@ -746,9 +745,8 @@ acl_t S3fsCurl::GetDefaultAcl()
 std::string S3fsCurl::SetStorageClass(const std::string& storage_class)
 {
     std::string old = S3fsCurl::storage_class;
-    S3fsCurl::storage_class = storage_class;
     // AWS requires uppercase storage class values
-    transform(S3fsCurl::storage_class.cbegin(), S3fsCurl::storage_class.cend(), S3fsCurl::storage_class.begin(), ::toupper);
+    S3fsCurl::storage_class = upper(storage_class);
     return old;
 }
 

src/string_util.cpp

@@ -18,6 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
+#include <algorithm>
 #include <cstdlib>
 #include <cstring>
 #include <cerrno>
@@ -98,10 +99,13 @@ off_t cvt_strtoofft(const char* str, int base)
 
 std::string lower(std::string s)
 {
-    // change each character of the std::string to lower case
-    for(size_t i = 0; i < s.length(); i++){
-        s[i] = static_cast<char>(tolower(s[i]));
-    }
+    std::transform(s.cbegin(), s.cend(), s.begin(), ::tolower);
+    return s;
+}
+
+std::string upper(std::string s)
+{
+    std::transform(s.cbegin(), s.cend(), s.begin(), ::toupper);
     return s;
 }
 

src/string_util.h

@@ -89,6 +89,7 @@ std::string trim_left(std::string s, const char *t = SPACES);
 std::string trim_right(std::string s, const char *t = SPACES);
 std::string trim(std::string s, const char *t = SPACES);
 std::string lower(std::string s);
+std::string upper(std::string s);
 std::string peeloff(std::string s);
 
 //