Misreporting of error position in mb3.2.7 [regression from 3.2.6]

[ms609]

When attempting to append to a previous run, the error message points to invalid character position:

      The error occurred when reading char. -326229434--326229435 on line 421

The error itself -- the message "Could not rename file" -- represent a different issue (#227)

What is the current observed behaviour?

MrBayes 3.2.7a on Windows 10 reports:

      Could not rename file ../flab/flab4.nex.run1.t
       Error appending to previous run
      Error in command "Mcmc"
      The error occurred when reading char. -326229434--326229435 on line 421
         in the file '../flab/flab4.nex'

MrBayes 3.2.6 x64 on Windows 10 correctly reports:

      Could not rename file ../flab/flab4.nex.run1.t
       Error appending to previous run
      Error in command "Mcmc"
      The error occurred when reading char. 6 on line 421
         in the file '../flab/flab4.nex'
   Error in command "Execute"

What is the expected/wanted behaviour?

The correct character number should be specified.

How may we reproduce this bug?

Nexus file extract:

417  >  mcmcp ngen=5000000 samplefreq=500 nruns=4 nchains=8 burninfrac=0.1;
418  >  mcmcp ngen=5000000 append=yes;
419  >  [mcmcp ngen=500000 append=no;]
420  >  
421  >  mcmc printfreq=1000 checkfreq=10000;

Steps to reproduce the bug:

1. Execute the above-sampled nexus file with line 418 commented out, and line 419 uncommented
2. Comment out line 419 and restore line 418
3. run exe path/to/flab4.nex

Would you be able to compile and run MrBayes to test fixes to this bug?

Happy to give it a try.

What is the environment that you run MrBayes in?

• Operating system (including variant and release): Windows 10 Pro build 19041.630 experience 120.2212.31.0
• Version of MrBayes: 3.2.7a 64bit

   ---------------------------------------------------------------------------
   Version

   MrBayes 3.2.7a

   Features:
   Host type: x86_64-w64-mingw32 (CPU: x86_64)
   Compiler:  gnu 7.3.0
   ---------------------------------------------------------------------------

Other information that may be of use to us in resolving this issue