Fix endless loop in generator bug

Marksu Heidelberg <[email protected]> contributed a patch to fix a bug that he also found with the -generator which resulted in an endless loop.

If the start address of a partial record is >= 0xFFFFFFF1, there is a 32 overflow when adding 255 (the maximum record data length). But the result with this address is still correct (see documentation "If the maximum is given as zero then the range extends to the end of the address space."), the endless loop appears when using address 0xFFFFFFF2 or higher.

But can be previously reproduced with this command: srec_cat -generate 0xFFFFFF02 0xFFFFFF03 -constant 0xAB

Author: sierrafoxtrot

srecord/input/generator.cc

@@ -53,8 +53,11 @@ srecord::input_generator::read(srecord::record &result)
     // Calculate the address range for this chunk of data.  Use the
     // biggest record size available.
     //
-    unsigned long addr = range.get_lowest();
-    interval partial(addr, addr + srecord::record::max_data_length);
+    interval::data_t addr = range.get_lowest();
+    interval::data_t end  = addr + srecord::record::max_data_length;
+    if (end < addr)
+        end = 0xFFFFFFFF;
+    interval partial(addr, end);
     partial *= range;
 
     //

test/02/t0254a.sh

@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# srecord - Manipulate EPROM load files
+# Copyright (C) 2014 Markus Heidelberg
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or (at
+# your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+TEST_SUBJECT="generate near end of address space"
+. test_prelude
+
+cat > test.ok << 'fubar'
+S00600004844521B
+S306FFFFFF02AB4F
+S5030001FB
+fubar
+if test $? -ne 0; then no_result; fi
+
+srec_cat -generate 0xFFFFFF02 0xFFFFFF03 -constant 0xAB -o test.out -header HDR
+if test $? -ne 0; then fail; fi
+
+diff test.ok test.out
+if test $? -ne 0; then fail; fi
+
+#
+# The things tested here, worked.
+# No other guarantees are made.
+#
+pass
+
+# vim: set ts=8 sw=4 et :