make sure to always give segment and offset in repo IntegrityError exception messages

this was only handled correctly at one place, by adding the segment number afterwards.
now the segment number is always included.

borg/repository.py

@@ -301,7 +301,7 @@ class Repository:
             try:
                 objects = list(self.io.iter_objects(segment))
             except IntegrityError as err:
-                report_error('Error reading segment {}: {}'.format(segment, err))
+                report_error(str(err))
                 objects = []
                 if repair:
                     self.io.recover_segment(segment, filename)
@@ -530,11 +530,12 @@ class LoggedIO:
         fd = self.get_fd(segment)
         fd.seek(0)
         if fd.read(MAGIC_LEN) != MAGIC:
-            raise IntegrityError('Invalid segment magic')
+            raise IntegrityError('Invalid segment magic [segment {}, offset {}]'.format(segment, 0))
         offset = MAGIC_LEN
         header = fd.read(self.header_fmt.size)
         while header:
-            size, tag, key, data = self._read(fd, self.header_fmt, header, offset, (TAG_PUT, TAG_DELETE, TAG_COMMIT))
+            size, tag, key, data = self._read(fd, self.header_fmt, header, segment, offset,
+                                              (TAG_PUT, TAG_DELETE, TAG_COMMIT))
             if include_data:
                 yield tag, key, offset, data
             else:
@@ -569,17 +570,19 @@ class LoggedIO:
         fd = self.get_fd(segment)
         fd.seek(offset)
         header = fd.read(self.put_header_fmt.size)
-        size, tag, key, data = self._read(fd, self.put_header_fmt, header, offset, (TAG_PUT, ))
+        size, tag, key, data = self._read(fd, self.put_header_fmt, header, segment, offset, (TAG_PUT, ))
         if id != key:
-            raise IntegrityError('Invalid segment entry header, is not for wanted id [offset {}]'.format(offset))
+            raise IntegrityError('Invalid segment entry header, is not for wanted id [segment {}, offset {}]'.format(
+                segment, offset))
         return data
 
-    def _read(self, fd, fmt, header, offset, acceptable_tags):
+    def _read(self, fd, fmt, header, segment, offset, acceptable_tags):
         # some code shared by read() and iter_objects()
         try:
             hdr_tuple = fmt.unpack(header)
         except struct.error as err:
-            raise IntegrityError('Invalid segment entry header [offset {}]: {}'.format(offset, err))
+            raise IntegrityError('Invalid segment entry header [segment {}, offset {}]: {}'.format(
+                segment, offset, err))
         if fmt is self.put_header_fmt:
             crc, size, tag, key = hdr_tuple
         elif fmt is self.header_fmt:
@@ -588,16 +591,19 @@ class LoggedIO:
         else:
             raise TypeError("_read called with unsupported format")
         if size > MAX_OBJECT_SIZE or size < fmt.size:
-            raise IntegrityError('Invalid segment entry size [offset {}]'.format(offset))
+            raise IntegrityError('Invalid segment entry size [segment {}, offset {}]'.format(
+                segment, offset))
         length = size - fmt.size
         data = fd.read(length)
         if len(data) != length:
-            raise IntegrityError('Segment entry data short read [offset {}]: expected: {}, got {} bytes'.format(
-                                 offset, length, len(data)))
+            raise IntegrityError('Segment entry data short read [segment {}, offset {}]: expected {}, got {} bytes'.format(
+                segment, offset, length, len(data)))
         if crc32(data, crc32(memoryview(header)[4:])) & 0xffffffff != crc:
-            raise IntegrityError('Segment entry checksum mismatch [offset {}]'.format(offset))
+            raise IntegrityError('Segment entry checksum mismatch [segment {}, offset {}]'.format(
+                segment, offset))
         if tag not in acceptable_tags:
-            raise IntegrityError('Invalid segment entry header, did not get acceptable tag [offset {}]'.format(offset))
+            raise IntegrityError('Invalid segment entry header, did not get acceptable tag [segment {}, offset {}]'.format(
+                segment, offset))
         if key is None and tag in (TAG_PUT, TAG_DELETE):
             key, data = data[:32], data[32:]
         return size, tag, key, data