Linux: getLanguageGroupID() returns wrong group

[CheeseSucker]

Operating Systems

Server: Windows 10
Client: Ubuntu 23.10

Synergy Version

Synergy 3 RC3 - v3.0.79.1-rc3

Steps to Reproduce

1. Set keyboard layout to "Norwegian" in both server and client
2. Type any special character. E.g. å

Expected: The same character appears in the client, å.
Actual: The client tries to use the english layout keystrokes to represent the letter, resulting in ˚ª instead of å and + instead of -.

Extra info

This appears to be related to how X11LayoutParser does mapping from layout names "no,us" to ISO-639-1 language codes.

Calculations in X11LayoutParser.getX11LanguageList():

From XkbRF_GetNamesProp():
  - Layouts: `no,us,us`
  - Variants: `,,`
Intermediate: nor, nob, nno, eng, eng   # In `evdev.xml` the norwegian keyboard layout has three associated languages
Result:       no, nb, nn, us            # After mapping to ISO-639-1 and removing duplicates

getLanguageGroupID(lang) returns the index of the language in the X11LanguageList resulting in this incorrect mapping:

getLanguageGroupID("no") => 0,
getLanguageGroupID("nb") => 1,
getLanguageGroupID("nn") => 2,
getLanguageGroupID("us") => 0, // After modulo operation

Correct mapping should be:

getLanguageGroupID("no") => 0,
getLanguageGroupID("nb") => 0,
getLanguageGroupID("nn") => 0,
getLanguageGroupID("us") => 1, //  2 is also fine in this case

Relevant logs

Startup (with extra logs):

synergy-core     [2024-03-31T11:50:10] - DEBUG1  - keyboard.getLayout(): "no,us,us"
synergy-core     [2024-03-31T11:50:10] - DEBUG1  - keyboard.getVariant(): ",,"
synergy-core     [2024-03-31T11:50:10] - INFO    - local languages: no, nb, nn, en
synergy-core     [2024-03-31T11:50:10] - INFO    - remote languages: nb, en
synergy-core     [2024-03-31T11:50:10] - DEBUG1  - xkb mapping
synergy-core     [2024-03-31T11:50:10] - DEBUG1  - Group names: 3
synergy-core     [2024-03-31T11:50:10] - DEBUG1  - Group name 0: Norwegian
synergy-core     [2024-03-31T11:50:10] - DEBUG1  - Group name 1: English (US)
synergy-core     [2024-03-31T11:50:10] - DEBUG1  - Group name 2: English (US)

Pressing å: (with extra logs)

synergy-core [2024-03-31T11:58:14] - DEBUG1 - mapKey 00e5 (229 | å) with mask 2000, start state: 0000, group: 0
synergy-core [2024-03-31T11:58:14] - DEBUG1 - language nb has group id 1
synergy-core [2024-03-31T11:58:14] - DEBUG1 - best key index 1 of 1 (exact)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - found key in group 1
synergy-core [2024-03-31T11:58:14] - DEBUG1 - language nb has group id 1
synergy-core [2024-03-31T11:58:14] - DEBUG1 - key item list count 2
synergy-core [2024-03-31T11:58:14] - DEBUG1 - item 0 0022
synergy-core [2024-03-31T11:58:14] - DEBUG1 - item 1 0026
synergy-core [2024-03-31T11:58:14] - DEBUG1 - flip: 0021 (0000 vs 0021 in 1021 - 0000)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - state: 0021,0000,1001
synergy-core [2024-03-31T11:58:14] - DEBUG1 - flip: 0001 (0021 vs 0000 in 1001 - 0000)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - desired state: 2000 0020,0000,1001
synergy-core [2024-03-31T11:58:14] - DEBUG1 - flip: 0000 (0020 vs 2000 in effe - 6020)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - mapped to 026, new state 0000
synergy-core [2024-03-31T11:58:14] - DEBUG1 - keystrokes:
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x00005c (92)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x000032 (50)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x000022 (34)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x000022 (34)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - skipping keystroke, language sync is disabled
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x000032 (50)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x000026 (38)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x00005c (92)
synergy-core [2024-03-31T11:58:14] - DEBUG1 - recv key up id=0x000000e5, mask=0x2000, button=0x001a
synergy-core [2024-03-31T11:58:14] - DEBUG1 - keystrokes:
synergy-core [2024-03-31T11:58:14] - DEBUG1 - - 0x000026 (38)

Correct keystrokes:

synergy-core [2024-03-31T12:01:50] - DEBUG1 - mapKey 00e5 (229 | å) with mask 2000, start state: 0000, group: 0
synergy-core [2024-03-31T12:01:50] - DEBUG1 - Forced selection of group 0
synergy-core [2024-03-31T12:01:50] - DEBUG1 - best key index 1 of 1 (exact)
synergy-core [2024-03-31T12:01:50] - DEBUG1 - found key in group 0
synergy-core [2024-03-31T12:01:50] - DEBUG1 - language nb has group id 1
synergy-core [2024-03-31T12:01:50] - DEBUG1 - key item list count 1
synergy-core [2024-03-31T12:01:50] - DEBUG1 - item 0 0022
synergy-core [2024-03-31T12:01:50] - DEBUG1 - state: 0000,0000,1021
synergy-core [2024-03-31T12:01:50] - DEBUG1 - flip: 0000 (0000 vs 0000 in 1021 - 0000)
synergy-core [2024-03-31T12:01:50] - DEBUG1 - desired state: 2000 0000,0000,1021
synergy-core [2024-03-31T12:01:50] - DEBUG1 - flip: 0000 (0000 vs 2000 in efde - 6020)
synergy-core [2024-03-31T12:01:50] - DEBUG1 - mapped to 022, new state 0000
synergy-core [2024-03-31T12:01:50] - DEBUG1 - keystrokes:
synergy-core [2024-03-31T12:01:50] - DEBUG1 - - 0x000022 (34)
synergy-core [2024-03-31T12:01:50] - DEBUG1 - recv key up id=0x000000e5, mask=0x2000, button=0x001a
synergy-core [2024-03-31T12:01:50] - DEBUG1 - keystrokes:
synergy-core [2024-03-31T12:01:50] - DEBUG1 - - 0x000022 (34)