Travis CI: Do not run make test if nothing changed in src/

.travis.yml

@@ -16,8 +16,6 @@ addons:
       - g++-4.9
       - gfortran-4.9
       - liblapack-dev
-#      - libopenblas-dev
-#      - libblas-dev
 
 branches:
   only:
@@ -38,4 +36,3 @@ script:
 
 after_failure:
   - tools/extras/travis_show_failures.sh
-  - ldd -v src/matrix/matrix-lib-test

tools/extras/travis_script.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# We take into account dependency pointers optionally set in the enironment.
+# We take into account dependency pointers optionally set in the environment.
 # Typical usage shown below; any one can be safely left unset.
 #   INCDIRS="~/xroot/usr/include"
 #   LIBDIRS="~/xroot/usr/lib /usr/lib/openblas-base"
@@ -11,6 +11,9 @@
 # Maximum make parallelism. Simply -j runs out of memory on Travis VM.
 MAXPAR=3
 
+# Directories with code that can be tested with Travis (space-separated)
+TESTABLE_DIRS="src/"
+
 # Run verbose (run and echo) and exit if failed.
 runvx() {
   echo "\$ $@"
@@ -31,6 +34,17 @@ mtoken() { echo ${2+$1=$2}; }
 runvx uname -a
 runvx env
 
+# Check for changes in src/ only; report success right away if none.
+# However, do run tests if TRAVIS_COMMIT_RANGE does not parse. This
+# most likely means the branch was reset by --force; re-run tests then.
+if git rev-parse "${TRAVIS_COMMIT_RANGE}" >/dev/null 2>&1 && \
+   ! git diff --name-only "${TRAVIS_COMMIT_RANGE}" -- ${TESTABLE_DIRS} | read REPLY
+then
+  echo; echo "No changes outside ${TESTABLE_DIRS} in the commit" \
+             "range ${TRAVIS_COMMIT_RANGE}; reporting success."
+  exit 0;
+fi
+
 # Prepare make command fragments.
 CF="$CFLAGS -g $(addsw -I $INCDIRS)"
 LDF="$LDFLAGS $(addsw -L $LIBDIRS)"