[libvirt] [PATCH 2/2] tests: silence qemuargv2xmltest noise

[Eric Blake]

* tests/qemuargv2xmltest.c (testCompareXMLToArgvHelper, mymain):
Use flag to mark which tests expect noisy stderr.
(testCompareXMLToArgvFiles): Add parameter to test whether stderr
was appropriately silent.
---

This doesn't actually validate the contents of the warning put to
stderr, but it's better than nothing as it tightens the test and
reduces the noise.

 tests/qemuargv2xmltest.c |   53 +++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/tests/qemuargv2xmltest.c b/tests/qemuargv2xmltest.c
index b75d2c5..8acf89f 100644
--- a/tests/qemuargv2xmltest.c
+++ b/tests/qemuargv2xmltest.c
@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <stdbool.h>

 #include <sys/types.h>
 #include <fcntl.h>
@@ -35,7 +36,8 @@ static int blankProblemElements(char *data)
 }

 static int testCompareXMLToArgvFiles(const char *xml,
-                                     const char *cmdfile) {
+                                     const char *cmdfile,
+                                     bool expect_stderr) {
     char xmlData[MAX_FILE];
     char cmdData[MAX_FILE];
     char *expectxml = &(xmlData[0]);
@@ -43,15 +45,52 @@ static int testCompareXMLToArgvFiles(const char *xml,
     char *cmd = &(cmdData[0]);
     int ret = -1;
     virDomainDefPtr vmdef = NULL;
+    int err_fd = -1;
+    int orig_stderr = -1;
+    const char *file = NULL;
+    off_t offset;

     if (virtTestLoadFile(cmdfile, &cmd, MAX_FILE) < 0)
         goto fail;
     if (virtTestLoadFile(xml, &expectxml, MAX_FILE) < 0)
         goto fail;

+    /* Redirect stderr for the duration of qemuParseCommandLineString,
+     * to check if there were any warnings.  */
+    file = "qemuargv2xmltest.err";
+    if (fflush(stderr) ||
+        (err_fd = open(file, O_CREAT | O_RDWR, 0600)) < 0 ||
+        (orig_stderr = dup(STDERR_FILENO)) < 0 ||
+        dup2(err_fd, STDERR_FILENO) != STDERR_FILENO)
+        goto fail;
+
     if (!(vmdef = qemuParseCommandLineString(driver.caps, cmd)))
         goto fail;

+    if (dup2(orig_stderr, STDERR_FILENO) != STDERR_FILENO)
+        goto fail;
+    if (close(orig_stderr)) {
+        orig_stderr = -1;
+        goto fail;
+    }
+    orig_stderr = -1;
+
+    if ((offset = lseek(err_fd, 0, SEEK_CUR)) < 0 ||
+        expect_stderr != !!offset)
+        goto fail;
+
+    if (close(err_fd)) {
+        err_fd = -1;
+        goto fail;
+    }
+    err_fd = -1;
+    if (unlink(file)) {
+        file = NULL;
+        goto fail;
+    }
+    file = NULL;
+
+    /* Proceed with remainder of test.  */
     if (!(actualxml = virDomainDefFormat(vmdef, 0)))
         goto fail;

@@ -67,6 +106,14 @@ static int testCompareXMLToArgvFiles(const char *xml,
     ret = 0;

  fail:
+    if (err_fd >= 0)
+        close(err_fd);
+    if (file)
+        unlink(file);
+    if (orig_stderr >= 0) {
+        dup2(orig_stderr, STDERR_FILENO);
+        close(orig_stderr);
+    }
     free(actualxml);
     virDomainDefFree(vmdef);
     return ret;
@@ -87,7 +134,7 @@ static int testCompareXMLToArgvHelper(const void *data) {
              abs_srcdir, info->name);
     snprintf(args, PATH_MAX, "%s/qemuxml2argvdata/qemuxml2argv-%s.args",
              abs_srcdir, info->name);
-    return testCompareXMLToArgvFiles(xml, args);
+    return testCompareXMLToArgvFiles(xml, args, !!info->extraFlags);
 }


@@ -215,7 +262,7 @@ mymain(int argc, char **argv)
     DO_TEST_FULL("restore-v2", 0, "exec:cat");
     DO_TEST_FULL("migrate", 0, "tcp:10.0.0.1:5000");

-    DO_TEST("qemu-ns-no-env");
+    DO_TEST_FULL("qemu-ns-no-env", 1, NULL);

     free(driver.stateDir);
     virCapabilitiesFree(driver.caps);
-- 
1.7.2.2