A patched Homebrew formula for GnuPG 2.1.11. This includes the patch for https://bugs.gnupg.org/gnupg/issue2229 from commit acac103: http://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=patch;h=acac103ba5772ae738ce5409d17feab80596cde6

gnupg21-patched.rb

class Gnupg21 < Formula
  desc "GNU Privacy Guard: a free PGP replacement"
  homepage "https://www.gnupg.org/"
  url "https://gnupg.org/ftp/gcrypt/gnupg/gnupg-2.1.11.tar.bz2"
  mirror "https://www.mirrorservice.org/sites/ftp.gnupg.org/gcrypt/gnupg/gnupg-2.1.11.tar.bz2"
  sha256 "b7b0fb2c8c5d47d7ec916d4a1097c0ddcb94a12bb1c0ac424ad86b1ee316b61a"

  bottle do
    sha256 "725cb9cebd07ca0ab9ea56a5742c765b77f0eed17f7c4428b575c40eea35ac8b" => :el_capitan
    sha256 "a699c10bc5324df5b88cd1612b7aa9c4b841986d7438eed542a4b59816cf41e2" => :yosemite
    sha256 "8c43114c858a4975c0fd1b3b52703e2be6b4ac2d8a40fb89dd9366db425b39a0" => :mavericks
  end

  head do
    url "git://git.gnupg.org/gnupg.git"

    depends_on "autoconf" => :build
    depends_on "automake" => :build
    depends_on "libtool" => :build
  end

  option "with-gpgsplit", "Additionally install the gpgsplit utility"

  depends_on "pkg-config" => :build
  depends_on "sqlite" => :build if MacOS.version == :mavericks
  depends_on "npth"
  depends_on "gnutls"
  depends_on "libgpg-error"
  depends_on "libgcrypt"
  depends_on "libksba"
  depends_on "libassuan"
  depends_on "pinentry"
  depends_on "gettext"
  depends_on "adns"
  depends_on "libusb-compat" => :recommended
  depends_on "readline" => :optional
  depends_on "homebrew/fuse/encfs" => :optional

  conflicts_with "gnupg2",
        :because => "GPG2.1.x is incompatible with the 2.0.x branch."
  conflicts_with "gpg-agent",
        :because => "GPG2.1.x ships an internal gpg-agent which it must use."
  conflicts_with "dirmngr",
        :because => "GPG2.1.x ships an internal dirmngr which it it must use."
  conflicts_with "fwknop",
        :because => "fwknop expects to use a `gpgme` with Homebrew/Homebrew's gnupg2."
  conflicts_with "gpgme",
        :because => "gpgme currently requires 1.x.x or 2.0.x."

  # Fixes a bug that may cause `make check` to fail
  # See https://bugs.gnupg.org/gnupg/issue2229
  patch :DATA

  def install
    (var/"run").mkpath

    ENV.append "LDFLAGS", "-lresolv"
    ENV["gl_cv_absolute_stdint_h"] = "#{MacOS.sdk_path}/usr/include/stdint.h"

    args = %W[
      --disable-dependency-tracking
      --disable-silent-rules
      --prefix=#{prefix}
      --sbindir=#{bin}
      --sysconfdir=#{etc}
      --enable-symcryptrun
      --with-pinentry-pgm=#{Formula["pinentry"].opt_bin}/pinentry
    ]

    args << "--with-readline=#{Formula["readline"].opt_prefix}" if build.with? "readline"

    if build.head?
      args << "--enable-maintainer-mode"
      system "./autogen.sh", "--force"
      system "automake", "--add-missing"
    end

    # Adjust package name to fit our scheme of packaging both gnupg 1.x and
    # and 2.1.x and gpg-agent separately.
    inreplace "configure" do |s|
      s.gsub! "PACKAGE_NAME='gnupg'", "PACKAGE_NAME='gnupg2'"
      s.gsub! "PACKAGE_TARNAME='gnupg'", "PACKAGE_TARNAME='gnupg2'"
    end

    system "./configure", *args

    system "make"
    system "make", "check"
    system "make", "install"

    bin.install "tools/gpgsplit" => "gpgsplit2" if build.with? "gpgsplit"

    # Move man files that conflict with 1.x.
    mv share/"doc/gnupg2/FAQ", share/"doc/gnupg2/FAQ21"
    mv share/"doc/gnupg2/examples/gpgconf.conf", share/"doc/gnupg2/examples/gpgconf21.conf"
    mv share/"info/gnupg.info", share/"info/gnupg21.info"
    mv man7/"gnupg.7", man7/"gnupg21.7"
  end

  def caveats; <<-EOS.undent
    Once you run the new gpg2 binary you will find it incredibly
    difficult to go back to using `gnupg2` from Homebrew/Homebrew.
    The new 2.1.x moves to a new keychain format that can't be
    and won't be understood by the 2.0.x branch or lower.

    If you use this `gnupg21` formula for a while and decide
    you don't like it, you will lose the keys you've imported since.
    For this reason, we strongly advise that you make a backup
    of your `~/.gnupg` directory.

    For full details of the changes, please visit:
      https://www.gnupg.org/faq/whats-new-in-2.1.html

    If you are upgrading to gnupg21 from gnupg2 you should execute:
      `killall gpg-agent && gpg-agent --daemon`
    After install. See:
      https://github.com/Homebrew/homebrew-versions/issues/681
    EOS
  end

  test do
    system "#{bin}/gpgconf"
  end
end

__END__
diff --git a/common/simple-pwquery.c b/common/simple-pwquery.c
index 90d04c0..b2d666c 100644
--- a/common/simple-pwquery.c
+++ b/common/simple-pwquery.c
@@ -618,6 +618,7 @@ simple_query (const char *query)
   int fd = -1;
   int nread;
   char response[500];
+  int have = 0;
   int rc;
 
   rc = agent_open (&fd);
@@ -628,40 +629,78 @@ simple_query (const char *query)
   if (rc)
     goto leave;
 
-  /* get response */
-  nread = readline (fd, response, 499);
-  if (nread < 0)
-    {
-      rc = -nread;
-      goto leave;
-    }
-  if (nread < 3)
+  while (1)
     {
-      rc = SPWQ_PROTOCOL_ERROR;
-      goto leave;
-    }
+      if (! have || ! strchr (response, '\n'))
+        /* get response */
+        {
+          nread = readline (fd, &response[have],
+                            sizeof (response) - 1 /* NUL */ - have);
+          if (nread < 0)
+            {
+              rc = -nread;
+              goto leave;
+            }
+          have += nread;
+          if (have < 3)
+            {
+              rc = SPWQ_PROTOCOL_ERROR;
+              goto leave;
+            }
+          response[have] = 0;
+        }
 
-  if (response[0] == 'O' && response[1] == 'K')
-    /* OK, do nothing.  */;
-  else if ((nread > 7 && !memcmp (response, "ERR 111", 7)
-            && (response[7] == ' ' || response[7] == '\n') )
-           || ((nread > 4 && !memcmp (response, "ERR ", 4)
-                && (strtoul (response+4, NULL, 0) & 0xffff) == 99)) )
-    {
-      /* 111 is the old Assuan code for canceled which might still
-         be in use by old installations. 99 is GPG_ERR_CANCELED as
-         used by modern gpg-agents; 0xffff is used to mask out the
-         error source.  */
+      if (response[0] == 'O' && response[1] == 'K')
+        /* OK, do nothing.  */;
+      else if ((nread > 7 && !memcmp (response, "ERR 111", 7)
+                && (response[7] == ' ' || response[7] == '\n') )
+               || ((nread > 4 && !memcmp (response, "ERR ", 4)
+                    && (strtoul (response+4, NULL, 0) & 0xffff) == 99)) )
+        {
+          /* 111 is the old Assuan code for canceled which might still
+             be in use by old installations. 99 is GPG_ERR_CANCELED as
+             used by modern gpg-agents; 0xffff is used to mask out the
+             error source.  */
 #ifdef SPWQ_USE_LOGGING
-      log_info (_("canceled by user\n") );
+          log_info (_("canceled by user\n") );
 #endif
-    }
-  else
-    {
+        }
+      else if (response[0] == 'S' && response[1] == ' ')
+        {
+          char *nextline;
+          int consumed;
+
+          nextline = strchr (response, '\n');
+          if (! nextline)
+            /* Point to the NUL.  */
+            nextline = &response[have];
+          else
+            /* Move past the \n.  */
+            nextline ++;
+
+          consumed = (size_t) nextline - (size_t) response;
+
+          /* Skip any additional newlines.  */
+          while (consumed < have && response[consumed] == '\n')
+            consumed ++;
+
+          have -= consumed;
+
+          if (have)
+            memmove (response, &response[consumed], have + 1);
+
+          continue;
+        }
+      else
+        {
 #ifdef SPWQ_USE_LOGGING
-      log_error (_("problem with the agent\n"));
+          log_error (_("problem with the agent (unexpected response \"%s\"\n"),
+                     response);
 #endif
-      rc = SPWQ_ERR_RESPONSE;
+          rc = SPWQ_ERR_RESPONSE;
+        }
+
+      break;
     }
 
  leave: