no error for non-existing mountpoints in MountCdrom

The mountpoint might be auto-generated by the mount command so pushing
an error on the stack will confuse the following code and let it believe
an unrecoverable error occured while potentially everything is okay.

Same goes for umount as a non-existing mountpoint is by definition not
mounted.

diff --git a/apt-pkg/contrib/cdromutl.cc b/apt-pkg/contrib/cdromutl.cc
index 176cc2024c2c273deb624150498d4dce6e732e48..f850e08a5ff7c7c395e9e9c70af8b9a9f41ab04b 100644 (file)
--- a/apt-pkg/contrib/cdromutl.cc
+++ b/apt-pkg/contrib/cdromutl.cc
@@ -74,7 +74,13 @@ bool IsMounted(string &Path)
    leave /etc/mtab inconsitant. We drop all messages this produces. */
 bool UnmountCdrom(string Path)
 {
-   if (IsMounted(Path) == false)
+   // do not generate errors, even if the mountpoint does not exist
+   // the mountpoint might be auto-created by the mount command
+   // and a non-existing mountpoint is surely not mounted
+   _error->PushToStack();
+   bool const mounted = IsMounted(Path);
+   _error->RevertToStack();
+   if (mounted == false)
       return true;
 
    for (int i=0;i<3;i++)
@@ -86,8 +92,9 @@ bool UnmountCdrom(string Path)
       if (Child == 0)
       {
         // Make all the fds /dev/null
-        for (int I = 0; I != 3; I++)
-           dup2(open("/dev/null",O_RDWR),I);
+        int const null_fd = open("/dev/null",O_RDWR);
+        for (int I = 0; I != 3; ++I)
+           dup2(null_fd, I);
 
         if (_config->Exists("Acquire::cdrom::"+Path+"::UMount") == true)
         {
@@ -121,19 +128,24 @@ bool UnmountCdrom(string Path)
 /* We fork mount and drop all messages */
 bool MountCdrom(string Path, string DeviceName)
 {
-   if (IsMounted(Path) == true)
+   // do not generate errors, even if the mountpoint does not exist
+   // the mountpoint might be auto-created by the mount command
+   _error->PushToStack();
+   bool const mounted = IsMounted(Path);
+   _error->RevertToStack();
+   if (mounted == true)
       return true;
-   
+
    int Child = ExecFork();
 
    // The child
    if (Child == 0)
    {
       // Make all the fds /dev/null
-      int null_fd = open("/dev/null",O_RDWR);
-      for (int I = 0; I != 3; I++)
+      int const null_fd = open("/dev/null",O_RDWR);
+      for (int I = 0; I != 3; ++I)
         dup2(null_fd, I);
-      
+
       if (_config->Exists("Acquire::cdrom::"+Path+"::Mount") == true)
       {
         if (system(_config->Find("Acquire::cdrom::"+Path+"::Mount").c_str()) != 0)