Opening and Empty .slvs File Causes a Crash (Was: "Crash after autosave-restore dialog wth file from v2.3")

[someSven]

System information

• **SolveSpace version:3.0~3e3ccdca
• **Operating system:Raspian wth OpenGL active

Expected behavior

Autosave file from v2.3 should open on v3 when I click to load it in the startup dialog.

Actual behavior

Crash.

Additional information

• I have OpenGL activated.
• The file was created in Solvespace 2.3, it works if I choose not to restore the autosave.
• It's not important to me, just thought you should know.

Shell:
(solvespace:18054): Gtk-CRITICAL **: 10:57:23.745: gtk_file_chooser_widget_set_current_name: assertion 'priv->action == GTK_FILE_CHOOSER_ACTION_SAVE || priv->action == GTK_FILE_CHOOSER_ACTION_CREATE_FOLDER' failed
File ./src/graphicswin.cpp, line 394, function Init:
Assertion failed: !SK.groupOrder.IsEmpty().
Message: Group order can't be empty since we will activate the last group..
Aborted

Chuwi-Guard.slvs.zip

[phkahler]

Not sure what the issue is, but it looks like a problem in 2.3 or even current version with auto-save. There are 2 files in the zip archive. One of them is zero length so I opened the other one and it works fine. Is the problem actually the empty file? Does it actually work on 2.3?

[someSven]

I tried again. The problem is the empty autosave file, which v2.3 created at some point. After putting it back into the same dir than the file I want to open, it crashes after trying to load the real file, if I click on "Load autosave". Same with both versions of Solvespace. If I click not to load it, then it works with both versions, the same if I delete the autosave-file.

[ruevs]

There is a problem when opening empty (0 bytes long) .SLVS files.
I'll fix it.

The problem is that here:

solvespace/src/file.cpp

Line 480 in 11a8a0a

ClearExisting();

we clear all groups. Then we try to read an empty file and therefore this while exists immediately:

solvespace/src/file.cpp

Line 487 in 11a8a0a

while(fgets(line, (int)sizeof(line), fh)) {

and we come to here:

solvespace/src/file.cpp

Line 548 in 11a8a0a

if(fileLoadError) {

where there is no fileLoadError and thus we are left with no groups, and so this assert fails:

solvespace/src/graphicswin.cpp

Line 394 in 11a8a0a

"Group order can't be empty since we will activate the last group.");

since is is not allowed to have no groups :-)

[ruevs]

Fixed.