From 5b7e6df00b4227d1a4485ab0c983f80715f63326 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Sun, 14 Sep 2014 17:43:19 -0400
Subject: [PATCH] Util

- The execute() function needed to fill the STDIN pipe before the fork, not
  after the fork, so the data is ready before the child process reads.
---
 src/Hooks.cpp |  2 +-
 src/util.cpp  | 33 +++++++++++++++++----------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/Hooks.cpp b/src/Hooks.cpp
index 2a835c2b8..4515df3a5 100644
--- a/src/Hooks.cpp
+++ b/src/Hooks.cpp
@@ -160,7 +160,7 @@ void Hooks::onExit ()
   std::vector <Task> changes;
   context.tdb2.get_changes (changes);
 
-  std::string input;
+  std::string input = "";
   std::vector <Task>::const_iterator t;
   for (t = changes.begin (); t != changes.end (); ++t)
     input += t->composeJSON () + "\n";
diff --git a/src/util.cpp b/src/util.cpp
index 51ffff114..a3b439e7c 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -271,6 +271,17 @@ int execute (
   pipe (pin);
   pipe (pout);
 
+  // Write input to fp, before the fork.
+  if (input != "")
+  {
+    FILE* pinf = fdopen (pin[1], "w");
+    if (pinf)
+    {
+      fputs (input.c_str (), pinf);
+      fclose (pinf);
+    }
+  }
+
   pid_t pid = fork ();
   if (pid == 0)
   {
@@ -278,7 +289,7 @@ int execute (
     dup2 (pin[0], STDIN_FILENO);
     dup2 (pout[1], STDOUT_FILENO);
 
-    char** argv = new char*[args.size () + 1];
+    char** argv = new char* [args.size () + 1];
     for (unsigned int i = 0; i < args.size (); ++i)
       argv[i] = (char*) args[i].c_str ();
 
@@ -287,32 +298,22 @@ int execute (
   }
 
   // This is only reached in the parent
-  close (pin[0]);
-  close (pout[1]);
-
-  // Write input to fp.
-  FILE* pinf = fdopen (pin[1], "w");
-  if (input != "" &&
-      input != "\n")
-  {
-    fputs (input.c_str (), pinf);
-  }
-
-  fclose (pinf);
-  close (pin[1]);
+  close (pin[0]);   // Close the read end of the input pipe.
+  close (pout[1]);  // Close the write end if the output pipe.
+  close (pin[1]);   // Close the write end of the input pipe.
 
   // Read output from fp.
   output = "";
   char* line = NULL;
   size_t len = 0;
-  FILE* poutf = fdopen(pout[0], "r");
+  FILE* poutf = fdopen (pout[0], "r");
   while (getline (&line, &len, poutf) != -1)
     output += line;
 
   free (line);
   line = NULL;
   fclose (poutf);
-  close (pout[0]);
+  close (pout[0]);  // Close the read-end of the output pipe.
 
   int status = -1;
   wait (&status);