Print zsync2's output on screen (#5824)

* Also remove the temporary files when doing a full retry
* Bump base
  Pickup the required zsync2/FBInk updates
  (https://github.com/koreader/koreader-base/pull/1038)
* Actually does what it says on the tin for Abort
  i.e., cleanup temporary files

base

@@ -1 +1 @@
-Subproject commit 0b0b8a72192909dcdce43792ae8765a9589eaaf8
+Subproject commit 84f56d3fb8f6883923ea5a0707ee26753259d47b

frontend/ui/otamanager.lua

@@ -308,8 +308,10 @@ function OTAManager:fetchAndProcessUpdate()
                                         timeout = 3,
                                     })
                                     -- Clear the installed package, as well as the complete/incomplete update download
-                                    os.execute("rm " .. self.installed_package)
-                                    os.execute("rm " .. self.updated_package .. "*")
+                                    os.execute("rm -f " .. self.installed_package)
+                                    os.execute("rm -f " .. self.updated_package .. "*")
+                                    -- As well as temporary files, in case zsync went kablooey too early...
+                                    os.execute("rm -f ./rcksum-*")
                                     -- And then relaunch zsync in full download mode...
                                     UIManager:scheduleIn(1, function()
                                         if OTAManager:zsync(true) == 0 then
@@ -326,7 +328,7 @@ function OTAManager:fetchAndProcessUpdate()
                                             UIManager:show(ConfirmBox:new{
                                                 text = _("Error updating KOReader. Would you like to delete temporary files?"),
                                                 ok_callback = function()
-                                                    os.execute("rm " .. ota_dir .. "ko*")
+                                                    os.execute("rm -f " .. ota_dir .. "ko*")
                                                 end,
                                             })
                                         end
@@ -334,7 +336,9 @@ function OTAManager:fetchAndProcessUpdate()
                                 end,
                                 choice2_text = _("Abort"),
                                 choice2_callback = function()
-                                    os.execute("rm " .. ota_dir .. "ko*")
+                                    os.execute("rm -f " .. ota_dir .. "ko*")
+                                    os.execute("rm -f " .. self.updated_package .. "*")
+                                    os.execute("rm -f ./rcksum-*")
                                 end,
                             })
                         end

platform/common/spinning_zsync

@@ -1,5 +1,16 @@
 #!/bin/sh
 
+# We're going to need to remember failures from the *left* side of a pipeline...
+# shellcheck disable=SC2039
+if set -o pipefail 2>/dev/null; then
+    WITH_PIPEFAIL="true"
+else
+    # But because we can't have nice things, some devices (hi, Kindle) may use an extremely old busybox build,
+    # one in which pipefail was not yet implemented,
+    # (it appeared in busybox 1.16.0, and is contingent on bash compatibility being enabled in ash).
+    WITH_PIPEFAIL="true"
+fi
+
 # Figure out whether that's a delta or a full download given the number of arguments passed...
 if [ $# -lt 7 ]; then
     ZSYNC_MESSAGE="Downloading update data"
@@ -7,43 +18,34 @@ else
     ZSYNC_MESSAGE="Computing zsync delta"
 fi
 
-# Small zsync wrapper so we can get a pretty spinner while it works...
-./fbink -q -y -7 -pmh "${ZSYNC_MESSAGE} !"
+# Small zsync wrapper so we can print its output while it works...
+./fbink -q -y -7 -pmh "${ZSYNC_MESSAGE} . . ."
 # Clear any potential leftover from the local OTA tarball creation.
 ./fbink -q -y -6 -pm ' '
 
-# Spin in the background while we work ;).
-(
-    # See https://stackoverflow.com/questions/2685435 for inspiration
-    # as well as https://www.npmjs.com/package/cli-spinners
-    # & https://github.com/swelljoe/spinner
-    # http://www.fileformat.info/info/unicode/block/block_elements/list.htm
-    ##
-    # Simple bars, they look better when a bit smoother, with a snappier interval (~250ms)
-    #SPINNER="<22> ▁ ▂ ▃ ▄ ▅ ▆ ▇ █ ▇ ▆ ▅ ▄ ▃ ▂ ▁"
-    #SPINNER="<22> ▏ ▎ ▍ ▌ ▋ ▊ ▉ █ ▉ ▊ ▋ ▌ ▍ ▎ ▏"
-    # Spinning blocks
-    SPINNER="▖ ▘ ▝ ▗"
-    #SPINNER="▜ ▟ ▙ ▛"
-    # Snaking blocks
-    #SPINNER="▌ ▀ ▐ ▄"
-    #SPINNER="▌ ▛ ▀ ▜ ▐ ▟ ▄ ▙"
-    while :; do
-        for spin in ${SPINNER}; do
-            usleep 500000 2>/dev/null || sleep 0.5
-            # NOTE: Throw stderr to the void because I'm cheating w/ U+FFFD for a blank character,
-            #       which FBInk replaces by a blank, but not before shouting at us on stderr ;).
-            ./fbink -q -y -7 -pmh "${ZSYNC_MESSAGE} ${spin}" 2>/dev/null
-        done
-    done
-) &
-
 # Launch zsync2, and remember its exit code...
-./zsync2 "$@"
-rc=$?
+# We'll be piping its output to FBInk in order to print it live, in a smaller font than usual...
+# NOTE: This depends on an undocumented FBInk hack (-z) in order to deal with the progress bars (and their CR) sanely.
+rc=0
 
-# Kill the spinner subshell now that we're done
-kill -15 $!
+if [ "${WITH_PIPEFAIL}" = "true" ]; then
+    # We can use pipefail, let the shell do the heavy lifting for us...
+    ./zsync2 "$@" 2>&1 | ./fbink -q -z -pm -F scientifica
+    rc=$?
+else
+    # We cannot use pipefail, extreme shell wizardry is required...
+    # Pure magic courtesy of https://unix.stackexchange.com/a/70675
+    # Much more compact than the stock answer from the Usenet shell FAQ: http://cfajohnson.com/shell/cus-faq-2.html#Q11
+    { { { {
+        ./zsync2 "$@" 2>&1 3>&- 4>&-
+        echo $? >&3
+    } | ./fbink -q -z -pm -F scientifica >&4; } 3>&1; } | {
+        read -r xs
+        exit "${xs}"
+    }; } 4>&1
+
+    rc=$?
+fi
 
-# And return with zsync's exit code, not kill's ;).
+# And return with zsync's exit code
 exit ${rc}