NDMP: Fix handling of different vendors regarding slashes

Different NDMP vendors send the FileHistory Information
in different ways, either with or without trailing or leading
slash on the filesystem or the filename side.

This commit fixes the problems with double or no slashes we had before

src/dird/ndmp_fhdb_common.c

@@ -64,19 +64,22 @@ extern "C" int bndmp_fhdb_add_file(struct ndmlog *ixlog, int tagc, char *raw_nam
          } else {
             ndmp_convert_fstat(fstat, nis->FileIndex, &FileType, attribs);
 
-            pm_strcpy(pathname, nis->filesystem);
+            bool filesystem_ends_with_slash = (nis->filesystem[strlen(nis->filesystem) - 1] == '/');
+            bool raw_name_starts_with_slash = (*raw_name == '/');
+            bool raw_name_ends_with_slash = (raw_name[strlen(raw_name) - 1] == '/') ;
 
+            pm_strcpy(pathname, nis->filesystem);
             /*
              * make sure we have a trailing slash
              */
-            if ( pathname.c_str()[strlen(pathname.c_str()) - 1] != '/' ) {
+            if (!filesystem_ends_with_slash) {
                 pm_strcat(pathname, "/");
             }
 
             /*
              * skip leading slash to avoid double slashes
              */
-            if (raw_name == (char*)'/') {
+            if (raw_name_starts_with_slash) {
                pm_strcat(pathname, raw_name + 1);
             } else {
                pm_strcat(pathname, raw_name);
@@ -87,7 +90,7 @@ extern "C" int bndmp_fhdb_add_file(struct ndmlog *ixlog, int tagc, char *raw_nam
                 * A directory needs to end with a '/'
                 * so append it if it is missing
                 */
-               if ( pathname.c_str()[strlen(pathname.c_str()) - 1] != '/' ) {
+               if (!raw_name_ends_with_slash) {
                   pm_strcat(pathname, "/");
                }
             }