Fix crash recovery limit logic: default unlimited, non-cumulative

BREAKING CHANGE: Crash recovery limit now defaults to unlimited (0).
- Removed cumulative CRASH_COUNT behavior that caused permanent disables
- Limit now applies per crash event only, not across sessions
- Optional per-crash limit via OBS_SAFE_LAUNCH_CRASH_LIMIT env var (0=unlimited)
- Added input validation for crash limit environment variable
- Updated documentation to reflect unlimited-by-default behavior
- Fixed typo in loopback compatibility section

This fixes the counterproductive reconnect counter that would lock out
recovery after 3 unrelated crashes in the same session or across reboots.

Author: xaoscience

docs/README.md

@@ -4,7 +4,7 @@ Stabilise high-throughput USB capture devices for OBS on Linux. Provides auto-re
 
 ## Features
 
-- **Automatic crash recovery** — OBS restarts automatically on USB device failure (3 retry limit)
+- **Automatic crash recovery** — OBS restarts automatically on USB device failure (unlimited by default)
 - **Stream resumption** — Monitors logs to detect active streams, auto-resumes if one was broadcasting
 - **v4l2loopback isolation** — FFmpeg feeds capture to `/dev/video10`, preventing OBS crashes from driver issues
 - **Auto-reconnect** — Monitors device and restarts feed on disconnect
@@ -187,11 +187,12 @@ lsusb | grep -i "your-device"
 
 **Safety launcher features:**
 - ✅ Monitors USB device health
-- ✅ Auto-restarts OBS on crash (max 3 attempts, 3s recovery timeout)
+- ✅ Auto-restarts OBS on crash (unlimited by default, 3s recovery timeout)
 - ✅ Detects if streaming was active before crash
 - ✅ Auto-resumes stream if it was broadcasting (enabled by default)
 - ✅ Captures full OBS output to log file for diagnostics
 - ✅ Logs to `~/.cache/obs-safe-launch/`
+- ✅ Optional per-crash limit via `OBS_SAFE_LAUNCH_CRASH_LIMIT` (`0` = unlimited)
 
 **Safety launcher flags:**
 | Flag | Purpose |
@@ -209,7 +210,7 @@ lsusb | grep -i "your-device"
 2. Wrapper waits 3 seconds for device/system to stabilize
 3. Checks OBS logs for active stream indication
 4. Restarts OBS with `--startstreaming` flag if stream was active
-5. If OBS crashes 3 times, requires human intervention
+5. Repeats this flow on future crashes (no cumulative cap unless `OBS_SAFE_LAUNCH_CRASH_LIMIT` is set)
 
 **Note:** Auto-reconnect requires sudo for USB hardware recovery (device resets, driver rebind). To avoid password prompts during long-running crash recovery, install the sudoers rule:
 ```bash

scripts/obs-safe-launch.sh

@@ -22,8 +22,7 @@ FEED_PID_FILE="/tmp/obs-safe-launch-feed.pid"
 STREAM_STATE_FILE="/tmp/obs-safe-launch-streaming.state"
 MONITOR_INTERVAL=5
 RECOVERY_TIMEOUT=3
-CRASH_THRESHOLD=3  # Max consecutive crashes before requiring user intervention
-CRASH_COUNT=0
+CRASH_THRESHOLD="${OBS_SAFE_LAUNCH_CRASH_LIMIT:-0}"  # 0 = unlimited; non-zero applies per crash event only
 WAS_STREAMING=0
 AUTO_RESUME_ENABLED=1  # Enable auto-resume by default
 
@@ -415,6 +414,7 @@ detect_streaming_state() {
 handle_obs_exit() {
   set +e  # Disable error exit for this function
   local exit_code="$1"
+  local crash_attempt=1
 
   # Detect if OBS was streaming before crash
   detect_streaming_state && WAS_STREAMING=1
@@ -423,16 +423,17 @@ handle_obs_exit() {
 
   # Check if this was a crash (non-zero exit or signal)
   if [ "$exit_code" -ne 0 ]; then
-    CRASH_COUNT=$((CRASH_COUNT + 1))
-    log_info "CRASH_COUNT incremented to: $CRASH_COUNT"
-
-    if [ $CRASH_COUNT -gt $CRASH_THRESHOLD ]; then
-      log_error "OBS crashed $CRASH_COUNT times (threshold: $CRASH_THRESHOLD). Requiring user intervention."
+    if [ "$CRASH_THRESHOLD" -gt 0 ] && [ "$crash_attempt" -gt "$CRASH_THRESHOLD" ]; then
+      log_error "Crash recovery blocked by OBS_SAFE_LAUNCH_CRASH_LIMIT=$CRASH_THRESHOLD"
       set -e
       return 1
     fi
 
-    log_recovery "Attempting recovery (crash $CRASH_COUNT/$CRASH_THRESHOLD)"
+    if [ "$CRASH_THRESHOLD" -gt 0 ]; then
+      log_recovery "Attempting recovery (event attempt $crash_attempt/$CRASH_THRESHOLD)"
+    else
+      log_recovery "Attempting recovery (unlimited mode)"
+    fi
     log_recovery "Waiting ${RECOVERY_TIMEOUT}s before restart..."
     sleep $RECOVERY_TIMEOUT
 
@@ -456,8 +457,7 @@ handle_obs_exit() {
     set -e
     return 0
   else
-    CRASH_COUNT=0
-    log_info "Clean exit, resetting crash count"
+    log_info "Clean exit"
     set -e
     return 0
   fi
@@ -476,6 +476,12 @@ main() {
   log_info "DEVICE_CHECK: $([ "$SKIP_DEVICE_CHECK" -eq 1 ] && echo "disabled" || echo "enabled")"
   log_info "OBS_ARGS: ${OBS_ARGS:-none}"
 
+  if ! [[ "$CRASH_THRESHOLD" =~ ^[0-9]+$ ]]; then
+    log_warn "Invalid OBS_SAFE_LAUNCH_CRASH_LIMIT='$CRASH_THRESHOLD' (expected integer). Falling back to 0 (unlimited)."
+    CRASH_THRESHOLD=0
+  fi
+  log_info "CRASH_LIMIT: $CRASH_THRESHOLD (0=unlimited, per crash event)"
+
   pre_flight_checks
   load_driver_optimizations
 
@@ -522,7 +528,6 @@ main() {
 
     if [ $EXIT_CODE -eq 0 ]; then
       log_info "OBS exited normally"
-      CRASH_COUNT=0
       break
     else
       log_info "Calling handle_obs_exit with exit code: $EXIT_CODE"