[PATCH v2 1/9] tests/qtest: Allow qtest_qemu_binary to use a custom environment variable

[Fabiano Rosas <farosas@suse.de>]

We're adding support for testing migration using two different QEMU
binaries. We'll provide the second binary in a new environment
variable.

Allow qtest_qemu_binary() to receive the name of the new variable. If
the new environment variable is not set, that's not an error, we use
QTEST_QEMU_BINARY as a fallback.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 tests/qtest/libqtest.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index b1eba71ffe..1f971b98e0 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -336,10 +336,17 @@ void qtest_remove_abrt_handler(void *data)
     }
 }
 
-static const char *qtest_qemu_binary(void)
+static const char *qtest_qemu_binary(const char *var)
 {
     const char *qemu_bin;
 
+    if (var) {
+        qemu_bin = getenv(var);
+        if (qemu_bin) {
+            return qemu_bin;
+        }
+    }
+
     qemu_bin = getenv("QTEST_QEMU_BINARY");
     if (!qemu_bin) {
         fprintf(stderr, "Environment variable QTEST_QEMU_BINARY required\n");
@@ -392,7 +399,7 @@ static QTestState *G_GNUC_PRINTF(1, 2) qtest_spawn_qemu(const char *fmt, ...)
 
     va_start(ap, fmt);
     g_string_append_printf(command, CMD_EXEC "%s %s",
-                           qtest_qemu_binary(), tracearg);
+                           qtest_qemu_binary(NULL), tracearg);
     g_string_append_vprintf(command, fmt, ap);
     va_end(ap);
 
@@ -907,7 +914,7 @@ char *qtest_hmp(QTestState *s, const char *fmt, ...)
 
 const char *qtest_get_arch(void)
 {
-    const char *qemu = qtest_qemu_binary();
+    const char *qemu = qtest_qemu_binary(NULL);
     const char *end = strrchr(qemu, '-');
 
     if (!end) {
-- 
2.35.3