Fixed QImageReader::format() inconsistency.

If state is set to ReadHeader before canRead() then setFormat("png")
never gets called. We should make sure that setFormat() gets set
whenever canRead() returns true.

Task-number: QTBUG-2263
Reviewed-by: Kent Hansen

5 files changed, 30 insertions, 18 deletions

diff --git a/src/gui/image/qbmphandler.cpp b/src/gui/image/qbmphandler.cpp
index 42e19b8..074b8f0 100644
--- a/src/gui/image/qbmphandler.cpp
+++ b/src/gui/image/qbmphandler.cpp
@@ -674,13 +674,15 @@ bool QBmpHandler::readHeader()
 
 bool QBmpHandler::canRead() const
 {
-    if (state == Ready) {
-        if (!canRead(device()))
-            return false;
+    if (state == Ready && !canRead(device()))
+        return false;
+
+    if (state != Error) {
         setFormat("bmp");
         return true;
     }
-    return state != Error;
+
+    return false;
 }
 
 bool QBmpHandler::canRead(QIODevice *device)
diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp
index dd31834..2cf8222 100644
--- a/src/gui/image/qpnghandler.cpp
+++ b/src/gui/image/qpnghandler.cpp
@@ -892,13 +892,15 @@ QPngHandler::~QPngHandler()
 
 bool QPngHandler::canRead() const
 {
-    if (d->state == QPngHandlerPrivate::Ready) {
-        if (!canRead(device()))
-            return false;
+    if (d->state == QPngHandlerPrivate::Ready && !canRead(device()))
+        return false;
+
+    if (d->state != QPngHandlerPrivate::Error) {
         setFormat("png");
         return true;
     }
-    return d->state != QPngHandlerPrivate::Error;
+
+    return false;
 }
 
 bool QPngHandler::canRead(QIODevice *device)
diff --git a/src/gui/image/qppmhandler.cpp b/src/gui/image/qppmhandler.cpp
index cbbbef4..a9e796c 100644
--- a/src/gui/image/qppmhandler.cpp
+++ b/src/gui/image/qppmhandler.cpp
@@ -409,13 +409,15 @@ bool QPpmHandler::readHeader()
 
 bool QPpmHandler::canRead() const
 {
-    if (state == Ready) {
-        if (!canRead(device(), &subType))
-            return false;
+    if (state == Ready && !canRead(device(), &subType))
+        return false;
+
+    if (state != Error) {
         setFormat(subType);
         return true;
     }
-    return state != Error;
+
+    return false;
 }
 
 bool QPpmHandler::canRead(QIODevice *device, QByteArray *subType)
diff --git a/src/gui/image/qxbmhandler.cpp b/src/gui/image/qxbmhandler.cpp
index 385340a..0dd4e99 100644
--- a/src/gui/image/qxbmhandler.cpp
+++ b/src/gui/image/qxbmhandler.cpp
@@ -261,13 +261,15 @@ bool QXbmHandler::readHeader()
 
 bool QXbmHandler::canRead() const
 {
-    if (state == Ready) {
-        if (!canRead(device()))
-            return false;
+    if (state == Ready && !canRead(device()))
+        return false;
+
+    if (state != Error) {
         setFormat("xbm");
         return true;
     }
-    return state != Error;
+
+    return false;
 }
 
 bool QXbmHandler::canRead(QIODevice *device)
diff --git a/src/gui/image/qxpmhandler.cpp b/src/gui/image/qxpmhandler.cpp
index a475cd0..b97afd3 100644
--- a/src/gui/image/qxpmhandler.cpp
+++ b/src/gui/image/qxpmhandler.cpp
@@ -1225,11 +1225,15 @@ bool QXpmHandler::readImage(QImage *image)
 
 bool QXpmHandler::canRead() const
 {
-    if (state == Ready && canRead(device())) {
+    if (state == Ready && !canRead(device()))
+        return false;
+
+    if (state != Error) {
         setFormat("xpm");
         return true;
     }
-    return state != Error;
+
+    return false;
 }
 
 bool QXpmHandler::canRead(QIODevice *device)