bsr: fix bad decrementing

We should only decrement the expected file counter if a file we are
actually restoring is split over two volumes.  That means we need to
keep track of which FileIndices we actually selected to be restored
instead of just assuming that we are restoring the whole volume.

core/src/dird/bsr.cc

@@ -154,13 +154,16 @@ static void PrintBsrItem(std::string& buffer, const char* fmt, ...)
  * for each Volume.
  */
 uint32_t write_findex(RestoreBootstrapRecordFileIndex* fi,
-                      int32_t FirstIndex,
-                      int32_t LastIndex,
+                      int32_t& FirstIndex,
+                      int32_t& LastIndex,
                       std::string& buffer)
 {
   auto count = uint32_t{0};
   auto bsrItems = std::string{};
 
+  std::optional<int32_t> actual_first;
+  std::optional<int32_t> actual_last;
+
   for (auto& range : fi->GetRanges()) {
     auto first = range.first;
     auto last = range.second;
@@ -170,6 +173,9 @@ uint32_t write_findex(RestoreBootstrapRecordFileIndex* fi,
       first = std::max(first, FirstIndex);
       last = std::min(last, LastIndex);
 
+      if (!actual_first.has_value()) { actual_first = first; }
+      actual_last = last;
+
       if (first == last) {
         bsrItems += "FileIndex=" + std::to_string(first) + "\n";
         count++;
@@ -181,6 +187,15 @@ uint32_t write_findex(RestoreBootstrapRecordFileIndex* fi,
     }
   }
   buffer += bsrItems.c_str();
+
+  if (actual_first.has_value()) {
+    // if we did not restore anything
+    // we should just leave the first/last index alone!
+    ASSERT(actual_last.has_value());
+    FirstIndex = *actual_first;
+    LastIndex = *actual_last;
+  }
+
   return count;
 }
 
@@ -379,7 +394,7 @@ static uint32_t write_bsr_item(RestoreBootstrapRecord* bsr,
                                RestoreContext& rx,
                                std::string& buffer,
                                bool& first,
-                               uint32_t& LastIndex)
+                               int32_t& LastIndex)
 {
   int i;
   char ed1[50], ed2[50];
@@ -423,18 +438,19 @@ static uint32_t write_bsr_item(RestoreBootstrapRecord* bsr,
                  edit_uint64(bsr->VolParams[i].StartAddr, ed1),
                  edit_uint64(bsr->VolParams[i].EndAddr, ed2));
 
-    count = write_findex(bsr->fi.get(), bsr->VolParams[i].FirstIndex,
-                         bsr->VolParams[i].LastIndex, buffer);
+    int32_t start = bsr->VolParams[i].FirstIndex;
+    int32_t end = bsr->VolParams[i].LastIndex;
+    count = write_findex(bsr->fi.get(), start, end, buffer);
     if (count) { PrintBsrItem(buffer, "Count=%u\n", count); }
 
     total_count += count;
 
     /* If the same file is present on two tapes or in two files
      * on a tape, it is a continuation, and should not be treated
      * twice in the totals. */
-    if (!first && LastIndex == bsr->VolParams[i].FirstIndex) { total_count--; }
+    if (!first && count > 0 && LastIndex == start) { total_count--; }
     first = false;
-    LastIndex = bsr->VolParams[i].LastIndex;
+    LastIndex = end;
   }
 
   return total_count;
@@ -452,7 +468,7 @@ static uint32_t write_bsr_item(RestoreBootstrapRecord* bsr,
 uint32_t WriteBsr(UaContext* ua, RestoreContext& rx, std::string& buffer)
 {
   bool first = true;
-  uint32_t LastIndex = 0;
+  int32_t LastIndex = 0;
   uint32_t total_count = 0;
   const char* p;
   JobId_t JobId;

core/src/dird/bsr.h

@@ -2,7 +2,7 @@
    BAREOS® - Backup Archiving REcovery Open Sourced
 
    Copyright (C) 2002-2010 Free Software Foundation Europe e.V.
-   Copyright (C) 2013-2019 Bareos GmbH & Co. KG
+   Copyright (C) 2013-2023 Bareos GmbH & Co. KG
 
    This program is Free Software; you can redistribute it and/or
    modify it under the terms of version three of the GNU Affero General Public
@@ -102,8 +102,8 @@ bool SendBootstrapFile(JobControlRecord* jcr,
                        bootstrap_info& info);
 void CloseBootstrapFile(bootstrap_info& info);
 uint32_t write_findex(RestoreBootstrapRecordFileIndex* fi,
-                      int32_t FirstIndex,
-                      int32_t LastIndex,
+                      int32_t& FirstIndex,
+                      int32_t& LastIndex,
                       std::string& buffer);
 
 } /* namespace directordaemon */

core/src/tests/test_fileindex_list.cc

@@ -1,7 +1,7 @@
 /*
    BAREOS® - Backup Archiving REcovery Open Sourced
 
-   Copyright (C) 2019-2022 Bareos GmbH & Co. KG
+   Copyright (C) 2019-2023 Bareos GmbH & Co. KG
 
    This program is Free Software; you can redistribute it and/or
    modify it under the terms of version three of the GNU Affero General Public
@@ -118,8 +118,10 @@ static std::string ToBsrStringBareos(const itBegin& t_begin, const itEnd& t_end)
   });
   auto maxId = *std::max_element(t_begin, t_end);
   auto buffer = std::string{};
-  TimedLambda("write_findex total",
-              [&]() { write_findex(bsr.fi.get(), 1, maxId, buffer); });
+  auto first_possible_file_index = 1;
+  TimedLambda("write_findex total", [&]() {
+    write_findex(bsr.fi.get(), first_possible_file_index, maxId, buffer);
+  });
   return std::string{buffer.c_str()};
 }