[PATCH] build: drop support for gmime-2.6

[David Bremner]

GMime 3.0 is over 2 years old now, and 2.6 has been deprecated in
notmuch for about 1.5 years.
---

Thanks to Rob Browning, I realized that the gzipped-mail-file series I
have recently posted does not compile with GMime 2.6. This made me
think that maybe it's the right time to drop support for GMime
2.6.

Travis will need some fix if we take this step. The alternative is to
add more gmime-2.6 compatibility code. I think the particular case
that I hit with the gzip patches (g_mime_stream_fs_open) is not that
hard to paper over, but I do wonder if that's a good use of our time
as developers.

I guess we could run a GMime PPA. Or we could migrate to some other CI
system. So far the latter is heavy on the talk, light on the action.

 configure | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/configure b/configure
index 5e7e5aa9..4163b584 100755
--- a/configure
+++ b/configure
@@ -489,9 +489,6 @@ EOF
     rm -rf test.db _default_backend _default_backend.cc
 fi
 
-# we need to have a version >= 2.6.5 to avoid a crypto bug. We need
-# 2.6.7 for permissive "From " header handling.
-GMIME_MINVER=2.6.7
 GMIME3_MINVER=3.0.3
 
 printf "Checking for GMime development files... "
@@ -502,17 +499,6 @@ if pkg-config --exists "gmime-3.0 > $GMIME3_MINVER"; then
     gmime_ldflags=$(pkg-config --libs gmime-3.0)
     gmime_major=3
     have_gmime_session_keys=1
-elif pkg-config --exists "gmime-2.6 >= $GMIME_MINVER"; then
-    printf "Yes (2.6).\n"
-    have_gmime=1
-    gmime_cflags=$(pkg-config --cflags gmime-2.6)
-    gmime_ldflags=$(pkg-config --libs gmime-2.6)
-    gmime_major=2
-    if pkg-config --exists "gmime-2.6 >= 2.6.21"; then
-        have_gmime_session_keys=1
-    else
-        have_gmime_session_keys=0
-    fi
 else
     have_gmime=0
     have_gmime_session_keys=0
@@ -788,7 +774,7 @@ EOF
 	echo
     fi
     if [ $have_gmime -eq 0 ]; then
-	echo "	GMime 2.6 library >= $GMIME_MINVER"
+	echo "	GMime 3.0 library >= $GMIME3_MINVER"
 	echo "	(including development files such as headers)"
 	echo "	https://github.com/jstedfast/gmime/"
 	echo
@@ -810,7 +796,7 @@ case a simple command will install everything you need. For example:
 
 On Debian and similar systems:
 
-	sudo apt-get install libxapian-dev libgmime-2.6-dev libtalloc-dev zlib1g-dev
+	sudo apt-get install libxapian-dev libgmime-3.0-dev libtalloc-dev zlib1g-dev
 
 Or on Fedora and similar systems:
 
-- 
2.20.1