Correct $status for certain pipeline-aborting failures

If we refused to launch a job because of a "pipeline aborting" error,
then it's the caller's responsibility to set $status.

Fixes #7540

CHANGELOG.rst

@@ -95,6 +95,7 @@ Scripting improvements
 -  An ``alias`` that delegates to a command with the same name no longer triggers an error about recursive completion (:issue:`7389`).
 - ``math`` now has a ``--base`` option to output the result in hexadecimal or octal (:issue:`7496`).
 - ``string`` subcommands now quit early when used with ``--quiet`` (:issue:`7495`).
+-  Failed redirections will now set ``$status`` (:issue:`7540`).
 
 Interactive improvements
 ------------------------

src/parse_execution.cpp

@@ -1391,7 +1391,13 @@ end_execution_reason_t parse_execution_context_t::run_1_job(const ast::job_t &jo
         }
 
         // Actually execute the job.
-        if (!exec_job(*this->parser, job, block_io)) {
+        if (!exec_job(*parser, job, block_io)) {
+            // No process in the job successfully launched.
+            // Ensure statuses are set (#7540).
+            if (auto statuses = job->get_statuses()) {
+                parser->set_last_statuses(statuses.value());
+                parser->libdata().status_count++;
+            }
             remove_job(*this->parser, job.get());
         }
 

tests/checks/pipestatus.fish

@@ -174,3 +174,31 @@ end | begin
 end
 echo $pipestatus : $status
 #CHECK: 0 0 : 0
+
+# Check that failed redirections correctly handle pipestatus, etc.
+# See #7540.
+command true > /not/a/valid/path
+echo $pipestatus : $status
+#CHECK: 1 : 1
+#CHECKERR: warning: An error occurred while redirecting file '/not/a/valid/path'
+#CHECKERR: open: No such file or directory
+
+# Here the first process will launch, the second one will not.
+command true | command true | command true > /not/a/valid/path
+echo $pipestatus : $status
+#CHECK: 0 0 1 : 1
+#CHECKERR: warning: An error occurred while redirecting file '/not/a/valid/path'
+#CHECKERR: open: No such file or directory
+
+# Pipeline breaks do not result in dangling jobs.
+command true | command cat > /not/a/valid/path ; jobs
+#CHECKERR: warning: An error occurred while redirecting file '/not/a/valid/path'
+#CHECKERR: open: No such file or directory
+#CHECK: jobs: There are no jobs
+
+# Regression test for #7038
+cat /dev/zero | dd > /not/a/valid/path
+echo 'Not hung'
+#CHECKERR: warning: An error occurred while redirecting file '/not/a/valid/path'
+#CHECKERR: open: No such file or directory
+#CHECK: Not hung