windeployqt: Proper error message when qtpaths.bat/.exe could not be run

If qtpaths cannt be found windeployqt should complain about that fact.
Previously it complained about "Unsupported platform".

Change-Id: I4db954633c31ceac69c4d3c0e55cbe942c3272fd
Reviewed-by: Joerg Bornemann <[email protected]>
(cherry picked from commit bf2f4678b0c1a17ad8d18809335cfb69d2c6527a)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>
(cherry picked from commit b876d260b698b3f942796a28cca517761f26f530)
(cherry picked from commit 781a17d783fe246ccce4e22ff3d23e8edc4b45a5)

2 files changed, 13 insertions, 9 deletions

diff --git a/src/tools/windeployqt/main.cpp b/src/tools/windeployqt/main.cpp
index 2d9fabd3f31..a4e49d554d4 100644
--- a/src/tools/windeployqt/main.cpp
+++ b/src/tools/windeployqt/main.cpp
@@ -1672,18 +1672,18 @@ int main(int argc, char **argv)
     const QMap<QString, QString> qtpathsVariables =
             queryQtPaths(options.qtpathsBinary, &errorMessage);
     const QString xSpec = qtpathsVariables.value(QStringLiteral("QMAKE_XSPEC"));
-    options.platform = platformFromMkSpec(xSpec);
-    if (options.platform == UnknownPlatform) {
-        std::wcerr << "Unsupported platform " << xSpec << '\n';
-        return 1;
-    }
-
     if (qtpathsVariables.isEmpty() || xSpec.isEmpty()
         || !qtpathsVariables.contains(QStringLiteral("QT_INSTALL_BINS"))) {
         std::wcerr << "Unable to query qtpaths: " << errorMessage << '\n';
         return 1;
     }
 
+    options.platform = platformFromMkSpec(xSpec);
+    if (options.platform == UnknownPlatform) {
+        std::wcerr << "Unsupported platform " << xSpec << '\n';
+        return 1;
+    }
+
     // Read the Qt module information from the Qt installation directory.
     const QString modulesDir
             = qtpathsVariables.value(QLatin1String("QT_INSTALL_ARCHDATA"))
diff --git a/src/tools/windeployqt/utils.cpp b/src/tools/windeployqt/utils.cpp
index 54186259ad8..7f01953e39d 100644
--- a/src/tools/windeployqt/utils.cpp
+++ b/src/tools/windeployqt/utils.cpp
@@ -424,14 +424,18 @@ const char *qmakeInfixKey = "QT_INFIX";
 QMap<QString, QString> queryQtPaths(const QString &qtpathsBinary, QString *errorMessage)
 {
     const QString binary = !qtpathsBinary.isEmpty() ? qtpathsBinary : QStringLiteral("qtpaths");
+    const QString colonSpace = QStringLiteral(": ");
     QByteArray stdOut;
     QByteArray stdErr;
     unsigned long exitCode = 0;
-    if (!runProcess(binary, QStringList(QStringLiteral("-query")), QString(), &exitCode, &stdOut, &stdErr, errorMessage))
+    if (!runProcess(binary, QStringList(QStringLiteral("-query")), QString(), &exitCode, &stdOut,
+                    &stdErr, errorMessage)) {
+        *errorMessage = QStringLiteral("Error running binary ") + binary + colonSpace + *errorMessage;
         return QMap<QString, QString>();
+    }
     if (exitCode) {
         *errorMessage = binary + QStringLiteral(" returns ") + QString::number(exitCode)
-            + QStringLiteral(": ") + QString::fromLocal8Bit(stdErr);
+            + colonSpace + QString::fromLocal8Bit(stdErr);
         return QMap<QString, QString>();
     }
     const QString output = QString::fromLocal8Bit(stdOut).trimmed().remove(u'\r');
@@ -467,7 +471,7 @@ QMap<QString, QString> queryQtPaths(const QString &qtpathsBinary, QString *error
         }
     } else {
         std::wcerr << "Warning: Unable to read " << QDir::toNativeSeparators(qconfigPriFile.fileName())
-            << ": " << qconfigPriFile.errorString()<< '\n';
+            << colonSpace << qconfigPriFile.errorString()<< '\n';
     }
     return result;
 }