fix: prefer foreground process during session resurrection - #1
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When a parent process has multiple children (e.g. `claude --resume` spawning MCP servers), `get_all_cmds_by_ppid` would store only the last child from `ps` output due to HashMap::insert overwriting. This caused session resurrection to capture a subprocess command instead of the user's actual foreground command. Fix by: - Adding the STAT column to ps output (`ps -ao ppid,stat,args`) - Collecting all children per parent PID - Preferring the foreground process (STAT contains '+') - Falling back to the first child when no foreground process exists The non-unix (Windows) path receives the same fix for the overwrite bug, using first-child as the heuristic since sysinfo does not expose foreground process group information. The return type and trait signature are unchanged, so all consumers (populate_session_layout_metadata, get_pane_running_command) work without modification. Relates to zellij-org#2925, zellij-org#4129
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- Negate empty if-branch in update_terminal_commands (match existing is_dirty pattern at line 124) - Avoid unnecessary .clone() in select_best_candidates by using position() + into_iter().nth() to move instead of copy
The sticky command change (not clearing `run` when the default shell is detected) caused a regression. The os_input_output fix alone addresses the root cause — this clearing behavior is needed for panes that legitimately return to the shell.
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Summary
get_all_cmds_by_ppidsilently overwriting when a parent PID has multiple children, causing session resurrection to capture a subprocess command instead of the user's foreground commandps -ao ppid,stat,args(adding STAT column) to prefer the foreground process (marked with+) over background childrenProblem
When tools like
claude --resumerun in a Zellij pane, they spawn child processes (MCP servers, LSP servers, etc.). The previous code usedHashMap::insertin a loop overpsoutput, so whichever child appeared last would silently overwrite earlier entries sharing the same parent PID. On resurrection, Zellij would then run the wrong command (e.g.node /path/to/mcp-serverinstead ofclaude --resume my-session).Relates to zellij-org#2925, zellij-org#4129
Approach
The STAT column from
pscontains+for processes in the foreground process group. By collecting all children per parent PID and preferring the one marked as foreground, we reliably capture the command the user actually launched.post_command_discovery_hookcontinues to work per-process; empty hook output now excludes that process from candidatesTest plan
zellij action dump-sessioncaptures the correct command