# HG changeset patch
# User "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
# Date 1290986799 -3600
# Node ID 62b3f52315b3147a493968e229db4d16a48200d9
# Parent  ea1c9143e1e3765f828bc6b8890471a8c73823ee
scripts: recover on partially downloaded files

Download to an intermediate temp file, and rename it to its final
name only of download succeeds.

This catches both a failed download, and also the case where the user
interrupts the download. Thus, the a partial download gets discarded,
and we no longer try to extract a partial tarball, which we would
previously have done.

Suggested by Thomas PETAZZONI.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

diff -r ea1c9143e1e3 -r 62b3f52315b3 scripts/functions
--- a/scripts/functions	Tue Nov 16 17:49:15 2010 +0100
+++ b/scripts/functions	Mon Nov 29 00:26:39 2010 +0100
@@ -359,6 +359,8 @@
 # to find the requested URL (think about snapshots, different layouts
 # for different gcc versions, etc...).
 CT_DoGetFile() {
+    local dest="${1##*/}"
+    local tmp="${dest}.tmp-dl"
     # OK, just look if we have them...
     # We are sure at least one is available, ./configure checked for it.
     local _curl=$(CT_Which curl)
@@ -366,6 +368,9 @@
     _curl="${_curl:-false}"
     _wget="${_wget:-false}"
 
+    # Remove potential left-over from a previous run
+    rm -f "${tmp}"
+
     # Some (very old!) FTP server might not support the passive mode, thus
     # retry without.
     # We also retry a few times, in case there is a transient error (eg. behind
@@ -377,11 +382,17 @@
     # not easy to detect them, and wget does not timeout by default while
     # connecting, so force a global ${CT_CONNECT_TIMEOUT}-second timeout.
     # For curl, no good progress indicator is available. So, be silent.
-       CT_DoExecLog ALL "${_curl}" --ftp-pasv    --retry 3 --connect-timeout ${CT_CONNECT_TIMEOUT} -L -f -s -O "$1" \
-    || CT_DoExecLog ALL "${_curl}"               --retry 3 --connect-timeout ${CT_CONNECT_TIMEOUT} -L -f -s -O "$1" \
-    || CT_DoExecLog ALL "${_wget}" --passive-ftp --tries=3 -T ${CT_CONNECT_TIMEOUT} -nc --progress=dot:binary  "$1" \
-    || CT_DoExecLog ALL "${_wget}"               --tries=3 -T ${CT_CONNECT_TIMEOUT} -nc --progress=dot:binary  "$1" \
-    || rm -f "${1##*/}"
+    if CT_DoExecLog ALL "${_curl}" --ftp-pasv    --retry 3 --connect-timeout ${CT_CONNECT_TIMEOUT} -L -f -s -o "${tmp}"   "$1"  \
+    || CT_DoExecLog ALL "${_curl}"               --retry 3 --connect-timeout ${CT_CONNECT_TIMEOUT} -L -f -s -o "${tmp}"   "$1"  \
+    || CT_DoExecLog ALL "${_wget}" --passive-ftp --tries=3 -T ${CT_CONNECT_TIMEOUT} -nc --progress=dot:binary -O "${tmp}" "$1"  \
+    || CT_DoExecLog ALL "${_wget}"               --tries=3 -T ${CT_CONNECT_TIMEOUT} -nc --progress=dot:binary -O "${tmp}" "$1"  \
+    ; then
+        # One of them succeeded, good!
+        mv "${tmp}" "${dest}"
+    else
+        # Woops...
+        rm -f "${tmp}"
+    fi
 }
 
 # This function tries to retrieve a tarball form a local directory