Merge bitcoin#782: Check if variable=yes instead of if var is set in travis.sh

34debf7 Modify .travis.yml to explictly pass no in env vars instead of setting to nothing (Elichai Turkel)
ef37761 Change travis.sh to check if variables are equal to yes instead of not-empty. Before this, setting `VALGRIND=wat` was considered as true, and to make it evaluate as false you had to unset the variable `VALGRIND=` but not it checks if `VALGRIND=yes` and if it's not `yes` then it's evaluated to false (Elichai Turkel)

Pull request description:

ACKs for top commit:
  real-or-random:
    ACK 34debf7
  jonasnick:
    ACK 34debf7

Tree-SHA512: 91becfbc9cb7587ee55b2bceb604ea0aed8860990d63a5f414b11db92180c090ea8bcc048c2fb67a094e892138e3be46f00562bf78b7c3369232457289cde447

Author: jonasnick

.travis.yml

@@ -31,9 +31,9 @@ env:
     - BIGNUM=no
     - BIGNUM=no       ENDOMORPHISM=yes RECOVERY=yes EXPERIMENTAL=yes SCHNORRSIG=yes
     - BIGNUM=no       STATICPRECOMPUTATION=no
-    - BUILD=distcheck CTIMETEST= BENCH=
+    - BUILD=distcheck CTIMETEST=no BENCH=no
     - CPPFLAGS=-DDETERMINISTIC
-    - CFLAGS=-O0 CTIMETEST=
+    - CFLAGS=-O0 CTIMETEST=no
     - ECMULTGENPRECISION=2
     - ECMULTGENPRECISION=8
     - VALGRIND=yes ENDOMORPHISM=yes BIGNUM=no ASM=x86_64 EXPERIMENTAL=yes ECDH=yes  RECOVERY=yes EXTRAFLAGS="--disable-openssl-tests" CPPFLAGS=-DVALGRIND BUILD=

contrib/travis.sh

@@ -24,16 +24,16 @@ if [ -n "$BUILD" ]
 then
     make -j2 "$BUILD"
 fi
-if [ -n "$VALGRIND" ]
+if [ "$VALGRIND" = "yes" ]
 then
     make -j2
     # the `--error-exitcode` is required to make the test fail if valgrind found errors, otherwise it'll return 0 (http://valgrind.org/docs/manual/manual-core.html)
     valgrind --error-exitcode=42 ./tests 16
     valgrind --error-exitcode=42 ./exhaustive_tests
 fi
-if [ -n "$BENCH" ]
+if [ "$BENCH" = "yes" ]
 then
-    if [ -n "$VALGRIND" ]
+    if [ "$VALGRIND" = "yes" ]
     then
         # Using the local `libtool` because on macOS the system's libtool has nothing to do with GNU libtool
         EXEC='./libtool --mode=execute valgrind --error-exitcode=42'
@@ -61,7 +61,7 @@ then
         $EXEC ./bench_schnorrsig >> bench.log 2>&1
     fi
 fi
-if [ -n "$CTIMETEST" ]
+if [ "$CTIMETEST" = "yes" ]
 then
     ./libtool --mode=execute valgrind --error-exitcode=42 ./valgrind_ctime_test > valgrind_ctime_test.log 2>&1
 fi