Disable SMSD exit_on_failure to prevent interpreter termination

[Copilot]

SMSD operations (GetStatus(), InjectSMS()) terminate the Python interpreter with exit code 255 when SMSD is not running, rather than raising catchable exceptions.

Root Cause

Gammu's GSM_SMSDConfig initializes exit_on_failure = TRUE, causing library code to call exit() on errors instead of returning error codes.

Changes

gammu/src/smsd.c

• Use SMSD_SetExitOnFailure(config, FALSE) after SMSD_NewConfig() to disable exit on failure and allow Python exception handling

test/test_smsd.py

• Add test verifying GetStatus() raises GSMError when daemon not running

Implementation

This fix uses the public SMSD_SetExitOnFailure() API introduced in Gammu PR #965, which provides a proper interface to disable the exit_on_failure flag without accessing internal structure fields. This approach:

• Uses Gammu's public API (no internal headers required)
• Is compatible with the opaque GSM_SMSDConfig structure
• Will work with Gammu versions that include this API (1.42.0+)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>If SMSD is not running, calls to InjectSMS and GetStatus cause python to quit</issue_title>
<issue_description>To replicate:

1. Install gammu-smsd (and gammu if needed)
2. Install or compile the binary distribution of python-gammu
3. Prepare a working gammu-smsdrc -file (depending on the distro)
4. Run the following python code

import gammu
smsd = gammu.SMSD('/path/to/gammu-smsdrc')
smsd.GetStatus()
# Or alternatively, attempt to send an SMS
smsd.InjectSMS([ {
    'Text': 'This is a test',
    'SMSC': {'Location': 1},
    'Number': '+1555123456'
}])

Expected results: python-gammu raises an exception or returns an appropriate error value.
Actual results: the python interpreter exits. See below:

~ # ipython
Python 3.6.3 (default, Nov 21 2017, 14:55:19) 
Type 'copyright', 'credits' or 'license' for more information
IPython 6.4.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import gammu

In [2]: smsd = gammu.SMSD('/etc/gammu-smsdrc')

In [3]: smsd.GetStatus()
python-gammu[1065]: Failed to allocate shared memory segment!, Error 2: No such file or directory

~ #
# Exit code is 255

OS: Alpine Linux 3.7
Gammu SMSD version: 1.38.5
python-gammu version: 2.11 (installed from source via pip)
Python version: 3.6.3

This is particularly annoying, since gammu.SMSD.Shutdown() raises an exception (ERR_NOTRUNNING) which is catchable. In the use case here, we cannot assume the SMSD is always running, thus GetStatus should indicate that without causing the whole program to quit.

The issue also occurs if the SHM is not accessible due to permissions, then the error returned is python-gammu[11522]: Failed to map shared memory segment!, Error 13: Permission denied.

---

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</issue_description>

<agent_instructions>Add testcase showing this behavior of SMSD and fix it by disabling exit_on_failure flag.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@nijel The problem is that `Config->exit_on_failure` is set by default by Gammu and python-gammu doesn't disable this.

• Fixes If SMSD is not running, calls to InjectSMS and GetStatus cause python to quit #29

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[nijel]

@copilot Rewrite the flag setting using the new API introduced in gammu/gammu#965. I will adjust the dependency and rebase once new Gammu version is released.

[Copilot]

@copilot Rewrite the flag setting using the new API introduced in gammu/gammu#965. I will adjust the dependency and rebase once new Gammu version is released.

Updated to use SMSD_SetExitOnFailure() API in commit 29636a9.