From 95f3729b99290c5c33fa6dc193f64c7fab8f78fc Mon Sep 17 00:00:00 2001
From: Mark Allen <mrallen1@yahoo.com>
Date: Tue, 11 Oct 2016 23:57:38 -0500
Subject: [PATCH] Exit if curl fails; download if archive 0 sized

If a curl command fails, exit from kerl instead of
blindly continuing.

Also if an archive has 0 size, try to download it
again, even if the file exists. (This is the
difference between -f and -s tests in bash.)

Closes #83
---
 kerl | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/kerl b/kerl
index eae28719..96303e85 100755
--- a/kerl
+++ b/kerl
@@ -201,7 +201,7 @@ get_git_releases()
 
 get_tarball_releases()
 {
-    curl -q -L -s $ERLANG_DOWNLOAD_URL/ | \
+    curl -f -q -L -s $ERLANG_DOWNLOAD_URL/ | \
         sed $SED_OPT -e 's/^.*<[aA] [hH][rR][eE][fF]=\"\otp_src_([-0-9A-Za-z_.]+)\.tar\.gz\">.*$/\1/' \
                      -e '/^R1|^[0-9]/!d' | \
         sed -e "s/^R\(.*\)/\1:R\1/" | sed -e "s/^\([^\:]*\)$/\1-z:\1/" | sort | cut -d':' -f2
@@ -214,13 +214,13 @@ update_checksum_file()
         return 0
     else
         echo "Getting checksum file from erlang.org..."
-        curl -L -o "$KERL_DOWNLOAD_DIR/MD5" "$ERLANG_DOWNLOAD_URL/MD5" || exit 1
+        curl -f -L -o "$KERL_DOWNLOAD_DIR/MD5" "$ERLANG_DOWNLOAD_URL/MD5" || exit 1
     fi
 }
 
 ensure_checksum_file()
 {
-    if [ ! -f "$KERL_DOWNLOAD_DIR"/MD5 ]; then
+    if [ ! -s "$KERL_DOWNLOAD_DIR"/MD5 ]; then
         update_checksum_file
     fi
 }
@@ -1227,16 +1227,18 @@ download()
 
 github_download()
 {
-    if [ ! -f "$KERL_DOWNLOAD_DIR/$1" ]; then
+    # if the file doesn't exist or the file has no size
+    if [ ! -s "$KERL_DOWNLOAD_DIR/$1" ]; then
         echo "Downloading $1 to $KERL_DOWNLOAD_DIR"
-        curl -L -o "$KERL_DOWNLOAD_DIR/$1" "$OTP_GITHUB_URL/archive/$1"
+        curl -f -L -o "$KERL_DOWNLOAD_DIR/$1" "$OTP_GITHUB_URL/archive/$1" || exit 1
     fi
 }
 
 tarball_download()
 {
-    if [ ! -f "$KERL_DOWNLOAD_DIR/$1" ]; then
-        curl -L -o "$KERL_DOWNLOAD_DIR/$1" "$ERLANG_DOWNLOAD_URL/$1"
+    if [ ! -s "$KERL_DOWNLOAD_DIR/$1" ]; then
+        echo "Downloading $1 to $KERL_DOWNLOAD_DIR"
+        curl -f -L -o "$KERL_DOWNLOAD_DIR/$1" "$ERLANG_DOWNLOAD_URL/$1" || exit 1
         update_checksum_file
     fi
     ensure_checksum_file