More robust creation of a subprocess, attempt to solve bug #13546.

 src/w32proc.c (new_child): If no vacant slots are found in
 child_procs[], make another pass looking for slots whose process
 has exited or died.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/w32proc.c b/src/w32proc.c
index 8c09a1b1beb..1e72d41e16b 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -798,6 +798,33 @@ new_child (void)
     if (!CHILD_ACTIVE (cp) && cp->procinfo.hProcess == NULL)
       goto Initialize;
   if (child_proc_count == MAX_CHILDREN)
+    {
+      DebPrint (("new_child: No vacant slots, looking for dead processes\n"));
+      for (cp = child_procs + (child_proc_count-1); cp >= child_procs; cp--)
+        if (!CHILD_ACTIVE (cp) && cp->procinfo.hProcess)
+          {
+            DWORD status = 0;
+
+            if (!GetExitCodeProcess (cp->procinfo.hProcess, &status))
+              {
+                DebPrint (("new_child.GetExitCodeProcess: error %lu for PID %lu\n",
+                           GetLastError (), cp->procinfo.dwProcessId));
+                status = STILL_ACTIVE;
+              }
+            if (status != STILL_ACTIVE
+                || WaitForSingleObject (cp->procinfo.hProcess, 0) == WAIT_OBJECT_0)
+              {
+                DebPrint (("new_child: Freeing slot of dead process %d\n",
+                           cp->procinfo.dwProcessId));
+                CloseHandle (cp->procinfo.hProcess);
+                cp->procinfo.hProcess = NULL;
+                CloseHandle (cp->procinfo.hThread);
+                cp->procinfo.hThread = NULL;
+                goto Initialize;
+              }
+          }
+    }
+  if (child_proc_count == MAX_CHILDREN)
     return NULL;
   cp = &child_procs[child_proc_count++];