configure.ac: make finding java deterministic

The sort order of the `find` command proves to be dependent on external
factors, which makes `./configure` pick different java versions on
different systems, making the whole build non-reproducible (see
https://reproducible-builds.org/ for more details).

Adding a call to `sort`, with the locale forced, fixes this issue.

Fixes: #1523

diff --git a/configure.ac b/configure.ac
index d214d57..c07687d 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2259,7 +2259,7 @@ then
        if test -d "$with_java_home"
        then
                AC_MSG_CHECKING([for jni.h])
-               TMPVAR=`find -L "$with_java_home" -name jni.h -type f -exec 'dirname' '{}' ';' 2>/dev/null | head -n 1`
+               TMPVAR=`find -L "$with_java_home" -name jni.h -type f -exec 'dirname' '{}' ';' 2>/dev/null | LC_ALL=C sort | head -n 1`
                if test "x$TMPVAR" != "x"
                then
                        AC_MSG_RESULT([found in $TMPVAR])
@@ -2269,7 +2269,7 @@ then
                fi
 
                AC_MSG_CHECKING([for jni_md.h])
-               TMPVAR=`find -L "$with_java_home" -name jni_md.h -type f -exec 'dirname' '{}' ';' 2>/dev/null | head -n 1`
+               TMPVAR=`find -L "$with_java_home" -name jni_md.h -type f -exec 'dirname' '{}' ';' 2>/dev/null | LC_ALL=C sort | head -n 1`
                if test "x$TMPVAR" != "x"
                then
                        AC_MSG_RESULT([found in $TMPVAR])
@@ -2279,7 +2279,7 @@ then
                fi
 
                AC_MSG_CHECKING([for libjvm.so])
-               TMPVAR=`find -L "$with_java_home" -type f \( -name libjvm.so -o -name libjvm.dylib \) -exec 'dirname' '{}' ';' 2>/dev/null | head -n 1`
+               TMPVAR=`find -L "$with_java_home" -type f \( -name libjvm.so -o -name libjvm.dylib \) -exec 'dirname' '{}' ';' 2>/dev/null | LC_ALL=C sort | head -n 1`
                if test "x$TMPVAR" != "x"
                then
                        AC_MSG_RESULT([found in $TMPVAR])
@@ -2291,7 +2291,7 @@ then
                if test "x$JAVAC" = "x"
                then
                        AC_MSG_CHECKING([for javac])
-                       TMPVAR=`find -L "$with_java_home" -name javac -type f 2>/dev/null | head -n 1`
+                       TMPVAR=`find -L "$with_java_home" -name javac -type f 2>/dev/null | LC_ALL=C sort | head -n 1`
                        if test "x$TMPVAR" != "x"
                        then
                                JAVAC="$TMPVAR"
@@ -2303,7 +2303,7 @@ then
                if test "x$JAR" = "x"
                then
                        AC_MSG_CHECKING([for jar])
-                       TMPVAR=`find -L "$with_java_home" -name jar -type f 2>/dev/null | head -n 1`
+                       TMPVAR=`find -L "$with_java_home" -name jar -type f 2>/dev/null | LC_ALL=C sort | head -n 1`
                        if test "x$TMPVAR" != "x"
                        then
                                JAR="$TMPVAR"