Add useful comment in test script ext.test.

* tests/ext.test: Add a comment explaining why an apparently
useless `if' statement is indeed required.

diff --git a/ChangeLog b/ChangeLog
index 6174ee0..c9a7def 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2010-06-13  Stefano Lattarini  <stefano.lattarini@gmail.com>
 
+       Add useful comment in test script ext.test.
+       * tests/ext.test: Add a comment explaining why an apparently
+       useless `if' statement is indeed required.
+
        Add useful comment in test script obsolete.test.
        * tests/obsolte.test: Add a comment explaining why we need
        an indirection in adding $AUTOUPDATE to $required.

diff --git a/tests/ext.test b/tests/ext.test
index 9340673..af2eab2 100755 (executable)
--- a/tests/ext.test
+++ b/tests/ext.test
@@ -38,6 +38,10 @@ $AUTOMAKE
 
 for ext in f for f90 f95 F F90 F95 r m upc
 do
+   # Some versions of the BSD shell wrongly exit when `set -e' is active
+   # if the last command within a compound statement fails and is guarded
+   # by an && only.  So we play safe and use the following idiom, instead
+   # of the apparently simpler `grep ... && Exit 1'.
    if grep "^$ext\.o:" Makefile.in; then Exit 1; else :; fi
    grep "^\.$ext\.o:" Makefile.in
 done