builtin "read -d" behaves differently after "set -e#

[Tiwo W.]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu'
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include
-I../bash/lib  -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector
--param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall
Machine Type: i686-pc-linux-gnu

Bash Version: 4.2
Patch Level: 37
Release Status: release

Description:

        I have seen "read -d '' var" to read multi-line heredocs into
        shell variables. An empty argument to -d seemed to mean "read
        up to the end of input". And this is what it does.

        When using this in a script of mine, I noticed that this fails
        when errexit is set ("set -e").

        I concede that from the documentation of "read" I should not
        have thought it would accept an empty -d argument, but

        * why does it work with "set +e" ?

        * what is the recommended way to disable splitting with "read"?

Repeat-By:

        set +e
        read -d '' var1 <<EOF
           no
           problem
           here
        EOF
        echo "$var1"

        set -e
        read -d '' var2 <<EOF
           but
           this
           fails
        EOF
        echo "$var2"

Fix:

        I would appreciate if the "read" documentation would clarify
        how to disable splitting.