From b4a32ddc1c5e8e8f9f410329b8f7817b8d60b13e Mon Sep 17 00:00:00 2001
From: Carl Eastlund <cce@racket-lang.org>
Date: Tue, 1 Dec 2009 02:10:50 +0000
Subject: [PATCH] Merged changes from branches/cce/plt+addon-dir: - Added
 PLTADDONDIR environment variable to control the location of   generated files
 from Planet and Scribble, specifically by overriding   the result of
 (find-system-path 'addon-dir). - Updated documentation of find-system-path to
 report this change.

svn: r17121
---
 .../scribblings/reference/filesystem.scrbl    |  8 ++++---
 src/mzscheme/src/file.c                       | 24 +++++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/collects/scribblings/reference/filesystem.scrbl b/collects/scribblings/reference/filesystem.scrbl
index 240ece9b6d..39e9e5d4d7 100644
--- a/collects/scribblings/reference/filesystem.scrbl
+++ b/collects/scribblings/reference/filesystem.scrbl
@@ -81,9 +81,11 @@ by @scheme[kind], which must be one of the following:
   ]}
 
  @item{@indexed-scheme['addon-dir] --- a directory for installing PLT Scheme
- extensions. It's the same as @scheme['pref-dir], except under Mac OS
- X, where it is @filepath{Library/PLT Scheme} in the user's home
- directory. This directory might not exist.}
+ extensions. This directory is specified by the @indexed-envvar{PLTADDONDIR}
+ environment variable.  If the environment variable is undefined or not a legal
+ path name, this directory defaults to @filepath{Library/PLT Scheme} in the
+ user's home directory under Mac OS X and @scheme['pref-dir] otherwise.  This
+ directory might not exist.}
 
  @item{@indexed-scheme['doc-dir] --- the standard directory for
  storing the current user's documents. Under Unix, it's the same as
diff --git a/src/mzscheme/src/file.c b/src/mzscheme/src/file.c
index ef2652bfc0..337118b3a2 100644
--- a/src/mzscheme/src/file.c
+++ b/src/mzscheme/src/file.c
@@ -5768,6 +5768,19 @@ find_system_path(int argc, Scheme_Object **argv)
 
     return CURRENT_WD();
   }
+
+  /* first option for addon_dir: PLTADDONDIR environment variable */
+  if (which == id_addon_dir) {
+    char* p;
+
+    if ((p = getenv("PLTADDONDIR"))) {
+      p = scheme_expand_filename(p, -1, NULL, NULL, 0);
+      if (p)
+        return scheme_make_path(p);
+    }
+
+    /* If PLTADDONDIR is undefined or malformed, fall through to default */
+  }
   
   {
     /* Everything else is in ~: */
@@ -5854,6 +5867,17 @@ find_system_path(int argc, Scheme_Object **argv)
       return CURRENT_WD();
     }
 
+    /* first option for addon_dir: PLTADDONDIR environment variable */
+    if (which == id_addon_dir) {
+      if ((p = getenv("PLTADDONDIR"))) {
+        p = scheme_expand_filename(p, -1, NULL, NULL, 0);
+        if (p)
+          return scheme_make_path(p);
+      }
+
+      /* If PLTADDONDIR is undefined or malformed, fall through to default */
+    }
+
     home = NULL;
 
     {