From e584774f0883867e296ee0999770850a0689d292 Mon Sep 17 00:00:00 2001
From: David Anderson <davea@ssl.berkeley.edu>
Date: Thu, 3 Apr 2008 21:59:05 +0000
Subject: [PATCH] - API: change boinc_resolve_filename() so that it detects
 symbolic links     and treats them as a special case.     Also, if the
 virtual file doesn't exist (as in the standalone case)     just return zero;
 otherwise if the app is running standalone     and checks the return value,
 it will error out.

    NOTE: apps that check the return value of boinc_resolve_filename()
    won't work on 6.12+ under Unix;
    recompiling with this change will fix the problem.

svn path=/trunk/boinc/; revision=15012
---
 checkin_notes | 15 +++++++++++++++
 lib/app_ipc.C | 22 ++++++++++++++++++----
 lib/filesys.C | 12 ++++++++++--
 lib/filesys.h |  1 +
 4 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/checkin_notes b/checkin_notes
index 53031f6c2c..c876d0e9b6 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -3055,3 +3055,18 @@ Rom    April 3 2008
         CACreateBOINCAccounts.cpp
         CACreateBOINCGroups.cpp
         CAMigrateBOINCData.cpp
+
+David  April 3 2008
+    - API: change boinc_resolve_filename() so that it detects symbolic links
+        and treats them as a special case.
+        Also, if the virtual file doesn't exist (as in the standalone case)
+        just return zero; otherwise if the app is running standalone
+        and checks the return value, it will error out.
+
+        NOTE: apps that check the return value of boinc_resolve_filename()
+        won't work on 6.12+ under Unix;
+        recompiling with this change will fix the problem.
+
+    lib/
+        app_ipc.C
+        filesys.C,h
diff --git a/lib/app_ipc.C b/lib/app_ipc.C
index 3fe22a55b6..65a5aa331a 100644
--- a/lib/app_ipc.C
+++ b/lib/app_ipc.C
@@ -302,24 +302,38 @@ void APP_CLIENT_SHM::reset_msgs() {
     memset(shm, 0, sizeof(SHARED_MEM));
 }
 
-// resolve "symbolic link"
+// Resolve virtual name (in slot dir) to physical path (in project dir).
+// Cases:
+// - Windows and pre-6.12 Unix:
+//   virtual name refers to a "soft link" (XML file acting as symbolic link)
+// - 6.12+ Unix:
+//   virtual name is a symbolic link
+// - Standalone: physical path is same as virtual name
 //
-int boinc_resolve_filename(const char *virtual_name, char *physical_name, int len) {
+int boinc_resolve_filename(
+    const char *virtual_name, char *physical_name, int len
+) {
     FILE *fp;
     char buf[512], *p;
 
     if (!virtual_name) return ERR_NULL;
     strlcpy(physical_name, virtual_name, len);
 
+#ifndef _WIN32
+    if (is_symlink(virtual_name)) {
+        return 0;
+    }
+#endif
+
     // Open the link file and read the first line
     //
     fp = boinc_fopen(virtual_name, "r");
-    if (!fp) return ERR_FOPEN;
+    if (!fp) return 0;
 
     // must initialize buf since fgets() on an empty file won't do anything
     //
     buf[0] = 0;
-    p =fgets(buf, 512, fp);
+    p =fgets(buf, sizeof(buf), fp);
     fclose(fp);
 
     // If it's the <soft_link> XML tag, return its value,
diff --git a/lib/filesys.C b/lib/filesys.C
index 2da24e8bc8..c01f89d4db 100644
--- a/lib/filesys.C
+++ b/lib/filesys.C
@@ -88,6 +88,14 @@ int is_dir(const char* path) {
     return (!retval && (sbuf.st_mode & S_IFDIR));
 }
 
+#ifndef _WIN32
+int is_symlink(const char* path) {
+    struct stat sbuf;
+    int retval = stat(path, &sbuf);
+    return (!retval && (sbuf.st_mode & S_IFLNK));
+}
+#endif
+
 // Open a directory
 //
 DIRREF dir_open(const char* p) {
@@ -337,7 +345,7 @@ int clean_out_dir(const char* dirpath) {
 
 // return total size of files in directory and optionally its subdirectories
 // Win: use special version because stat() is slow, can be avoided
-// Unix: skip symbolic links
+// Unix: follow symbolic links
 //
 int dir_size(const char* dirpath, double& size, bool recurse) {
 #ifdef WIN32
@@ -386,7 +394,7 @@ int dir_size(const char* dirpath, double& size, bool recurse) {
                 if (retval) continue;
                 size += x;
             }
-        } else if (is_file(subdir)) {
+        } else {
             retval = file_size(subdir, x);
             if (retval) continue;
             size += x;
diff --git a/lib/filesys.h b/lib/filesys.h
index b807301064..c7cdd112b9 100644
--- a/lib/filesys.h
+++ b/lib/filesys.h
@@ -57,6 +57,7 @@ extern "C" {
   extern char boinc_failed_file[256];
   extern int is_file(const char* path);
   extern int is_dir(const char* path);
+  extern int is_symlink(const char* path);
   extern int boinc_truncate(const char*, double);
   extern int boinc_file_exists(const char* path);
   extern int boinc_file_or_symlink_exists(const char* path);