Fix off by one error in dbase::File

dbase::File calculated the position of the record/field
assuming the record size by using the header's info
which includes the implicit deletion flag size, and dbase::File
added the deletion flag size again resulting of bad readings.

src/file.rs

@@ -53,7 +53,7 @@ impl<'a, T> FieldRef<'a, T> {
             .map(|i| i.field_length as u64)
             .sum::<u64>();
 
-        record_position + position_in_record
+        record_position + position_in_record + DELETION_FLAG_SIZE as u64
     }
 }
 
@@ -227,7 +227,7 @@ where
     /// - true -> the record is marked as deleted
     /// - false -> the record is **not** marked as deleted
     pub fn is_deleted(&mut self) -> Result<bool, Error> {
-        let deletion_flag_pos = self.position_in_source() - DELETION_FLAG_SIZE as u64;
+        let deletion_flag_pos = self.position_in_source();
         self.file
             .inner
             .seek(SeekFrom::Start(deletion_flag_pos))

src/header.rs

@@ -4,7 +4,6 @@ use crate::encoding::DynEncoding;
 use std::io::{Read, Write};
 
 use crate::field::types::Date;
-use crate::field::DELETION_FLAG_SIZE;
 use crate::memo::MemoFileType;
 
 // Used this as source: https://blog.codetitans.pl/post/dbf-and-language-code-page/
@@ -412,9 +411,8 @@ impl Header {
         if index >= self.num_records as usize {
             None
         } else {
-            let offset = self.offset_to_first_record as usize
-                + (index * (self.size_of_record as usize + DELETION_FLAG_SIZE))
-                + DELETION_FLAG_SIZE;
+            let offset =
+                self.offset_to_first_record as usize + (index * self.size_of_record as usize);
             Some(offset)
         }
     }

tests/test_file.rs

@@ -299,37 +299,48 @@ fn test_file_char_trimming() -> Result<(), Box<dyn std::error::Error>> {
         }
     );
 
+    let mut file = dbase::File::open_read_only("tests/data/stations.dbf")?;
+    let reading = dbase::ReadingOptions::default().character_trim(dbase::TrimOption::End);
+    file.set_options(reading);
+
+    let expected_trim_end = StationRecord {
+        name: format!("{}", "  Franconia-Springfield",),
+        marker_col: format!("{}", "  #0000ff",),
+        marker_sym: format!("{}", "  rail-metro",),
+        line: format!("{}", "  blue",),
+    };
+
+    let record = file.record(1).unwrap().read_as::<StationRecord>()?;
+    assert_eq!(record, expected_trim_end);
+
     let mut file = dbase::File::open_read_only("tests/data/stations.dbf")?;
     let reading = dbase::ReadingOptions::default().character_trim(dbase::TrimOption::Begin);
     file.set_options(reading);
 
-    let expected = StationRecord {
+    let expected_trim_begin = StationRecord {
         name: format!(
             "{:width$}",
             "Franconia-Springfield",
-            width = file.fields()[0].length() as usize
+            width = file.fields()[0].length() as usize - 2
         ),
         marker_col: format!(
             "{:width$}",
             "#0000ff",
-            width = file.fields()[0].length() as usize
+            width = file.fields()[0].length() as usize - 2
         ),
         marker_sym: format!(
             "{:width$}",
             "rail-metro",
-            width = file.fields()[0].length() as usize
+            width = file.fields()[0].length() as usize - 2
         ),
         line: format!(
             "{:width$}",
             "blue",
-            width = file.fields()[0].length() as usize
+            width = file.fields()[0].length() as usize - 2
         ),
     };
-
     let record = file.record(1).unwrap().read_as::<StationRecord>()?;
-
-    assert_eq!(record, expected);
-
+    assert_eq!(record, expected_trim_begin);
     Ok(())
 }