db_text: fix issues when database file is missing an ending newline

* do not crash if file contains columns only and is missing the ending newline
* do not skip the last row of a database file if it lacks an ending newline

Reported by gergelypeli on GitHub
Closes issue #308
(cherry picked from commit a2172b2)

modules/db_text/dbt_file.c

@@ -265,6 +265,14 @@ dbt_table_p dbt_load_file(const str *tbn, const str *dbn)
 					colp0 = colp;
 					dtp->nrcols++;
 					c = fgetc(fin);
+
+					/* at least 1 column was found. eat all trailing spaces */
+					while (c == DBT_DELIM_C)
+						c = fgetc(fin);
+
+					/* properly load files which do not end in a newline */
+					if (c == EOF)
+						c = DBT_DELIM_R;
 				}
 				else
 					goto clean;
@@ -468,6 +476,11 @@ dbt_table_p dbt_load_file(const str *tbn, const str *dbn)
 					default:
 						goto clean;
 				}
+
+				/* do not skip last row if it does not end with a newline */
+				if (c == EOF)
+					c = DBT_DELIM_R;
+
 				if(c==DBT_DELIM)
 					c = fgetc(fin);
 				ccol++;