A very odd situation is occurring:
(Running Windows 7 Enterprise, SP1, 64bit)
A GUI I use at work (built specifically for this purpose and intended to run in a Windows environment) generates .dat files. I need to edit one slightly before I use it. I open it in plain old Notepad, make my edit and save it (everything looks fine). When I REOPEN it with any program (Notepad, Notepad++, etc) all "new lines"/"enters"/line-breaks have been removed - everything appears to be jumbled together as one long line.
If I simply open it and close it in Notepad without saving, nothing changes and the line-breaks are where they should be. Opening the doc in Notepad++ or another program and saving it does not affect the line-breaks. Copying the contents to Notepad++ and back to Notepad also fixes this problem - subsequent saves in Notepad do not bread the Linebreaks.
What makes this an even more awkward problem is that this behavior does not apply to ALL the .dat files my GUI produces. Just some of them.
Any good ideas on what is happening and how to fix it?
If the solution to this is to modify the way my GUI produces the files, that is an acceptable answer as the GUI is something I can submit a bug-report for.
However... it seems unlikely as I don't think my boss has ever had this problem before and he uses the same version of the GUI and Notepad to make slight modifications to the files. I also have only had this happen recently and inconsistently: a file that had this problem previously does NOT loose its linebreaks when saved with Notepad in this current iteration of files.
Edit: more info: I sent the file to my boss and had him open and save with Notepad on his computer and nothing funny happened - all linebreaks remained after saving, closing and reopening. Either the process of sending it fixed something in the file, or it is something funny with my computer.
Looking at the hex of the saved and unsaved files: As far as I can tell, the unsaved version has 0D0A between lines and the saved version is missing all instances of 0D0A except for a single instance at the very end (I wonder if this was added by Notepad++ as the file was opened/converted).
Edit again: the hex version of the "unsaved" file after editing out sensitive info:
2320504C4541534520434845434B3A20 544845524D5F43617020616E64204465 70436170206265666F72652072756E6E 696E67202121210D0D0A0D0D0A706172 616D20696E697469616C203A3D20313B 0D0D0A706172616D2054203A3D313735 32303B0D0D0A706172616D206474203A 3D20333630303B0D0D0A0D0D0A706172 616D204950505F4F524F203A3D20302E 313233343B0D0D0A706172616D205448 45524D5F4F524F203A3D20302E313233 343B0D0D0A706172616D20544845524D 5F436170203A3D2031323334353B0D0D 0A706172616D20446570436170203A3D 31323334353B0D0D0A234D572C204465 70656E6461626C652043617061636974 79206F662073747566660D0D0A090909 234E756D6265727320666F7220726566 6572656E63653A207468696E67732E0D 0D0A09090923446570656E6461626C65 204361703A2073747566660D0D0A7061 72616D20425546464552203A3D20303B 0D0D0A706172616D20636F6E76657274 203A3D20312E303B0D0D0A0D0D0A7061 72616D09525245534E504F494E545309 3A3D20353B0D0D0A706172616D095252 4553424B50093A3D0D0D0A31092D3132 33343530200D0D0A32092D3132333435 3030200D0D0A330930200D0D0A340931 32333435200D0D0A3509313233343520 0D0D0A3B0D0D0A0D0D0A706172616D09 525245534C4F5045093A3D0D0D0A3109 2D3132333435452D30350D0D0A32092D 3132333435452D30350D0D0A33092D31 32333435452D30350D0D0A3409313233 34350D0D0A3B0D0D0A0D0D0A2357696E 64792073747566660D0D0A706172616D 2057494E445F49433A3D0D0D0A706C61 63650931323334350D0D0A3B0D0D0A0D 0D0A706172616D207468696E67793A3D 0D0D0A706C6163650931323334350D0D 0A3B0D0D0A0D0D0A706172616D204F50 545F5265733A3D0D0D0A7468696E6709 300D0D0A3B0D0D0A0D0A
This is the hex code after saving in notepad and reopening:
2320504C4541534520434845434B3A20 544845524D5F43617020616E64204465 70436170206265666F72652072756E6E 696E6720212121706172616D20696E69 7469616C203A3D20313B706172616D20 54203A3D31373532303B706172616D20 6474203A3D20333630303B706172616D 204950505F4F524F203A3D20302E3132 33343B706172616D20544845524D5F4F 524F203A3D20302E313233343B706172 616D20544845524D5F436170203A3D20 31323334353B09706172616D20446570 436170203A3D383632362E313B234D57 2C20446570656E6461626C6520436170 6163697479206F662073747566660909 09234E756D6265727320666F72207265 666572656E63653A207468696E677309 090923446570656E6461626C65204361 703A207374756666706172616D204255 46464552203A3D20303B706172616D20 636F6E76657274203A3D20312E303B70 6172616D09525245534E504F494E5453 093A3D20353B706172616D0952524553 424B50093A3D31092D31323334353020 32092D31323334353030203309302034 0931323334352035093132333435203B 706172616D09525245534C4F5045093A 3D31092D3132333435452D303532092D 3132333435452D303533092D31323334 35452D303534092D3132333435452D30 353B2357696E64792073747566667061 72616D2057494E445F49433A3D706C61 63650931323334353B706172616D2074 68696E67793A3D706C61636509313233 34353B706172616D204F50545F526573 3A3D7468696E6709303B0D0A