[PATCH] Travis: also test on 32-bit Linux

[Johannes Schindelin <johannes.schindelin@gmx.de>]

When Git v2.9.1 was released, it had a bug that showed only on Windows
and on 32-bit systems: our assumption that `unsigned long` can hold
64-bit values turned out to be wrong.

This could have been caught earlier if we had a Continuous Testing
set up that includes a build and test run on 32-bit Linux.

Let's do this (and take care of the Windows build later). This patch
asks Travis CI to install a Docker image with 32-bit libraries and then
goes on to build and test Git using this 32-bit setup.

A big thank you to Lars Schneider without whose help this patch would
not have happened.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
Published-As: https://github.com/dscho/git/releases/tag/travis-32-bit-v1
Fetch-It-Via: git fetch https://github.com/dscho/git travis-32-bit-v1

 .travis.yml | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index 9c63c8c3f68..87d9e9051a6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -39,6 +39,17 @@ env:
 
 matrix:
   include:
+    - env: Linux32
+      os: linux
+      compiler: clang
+      sudo: required
+      services:
+        - docker
+      before_install:
+        - docker pull daald/ubuntu32:xenial
+      before_script:
+      script:
+        - "sudo docker run -i -v \"${PWD}:/usr/src/git\" daald/ubuntu32:xenial /bin/bash -c \"linux32 --32bit i386 sh -c 'apt update && apt install -y build-essential libcurl4-openssl-dev libssl-dev libexpat-dev gettext python && cd /usr/src/git && DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS=\\\"--timer --jobs 3 --state=failed,slow,save\\\" GIT_TEST_OPTS=--verbose-log GIT_TEST_CLONE_2GB=YesPlease make -j2 test'\""
     - env: Documentation
       os: linux
       compiler: clang

base-commit: 3bc53220cb2dcf709f7a027a3f526befd021d858
-- 
2.12.0.windows.1.3.g8a117c48243