check for XXXApp_8C.html (Application) in the -doc argument handling first.

This is useful when the application has the same name as a class. For example,
polyDualMeshApp.C implements the polyDualMesh application using the
polyDualMesh class. Thus polyDualMeshApp_8C.html documents the app, whereas
polyDualMesh_8C.html is the annotated source code for the class itself.

etc/controlDict

@@ -5,22 +5,15 @@
 |   \\  /    A nd           | Web:      http://www.openfoam.org               |
 |    \\/     M anipulation  |                                                 |
 \*---------------------------------------------------------------------------*/
-
-// Foam Dictionary.
-
 FoamFile
 {
     version     2.0;
     format      ascii;
-
-    root            "";
-    case            "";
-    instance        "";
-    local           "";
     class       dictionary;
     object      controlDict;
 }
 
+// NB: the #functions do not work here
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 hosts
@@ -70,7 +63,11 @@ Documentation
         "~OpenFOAM/Doxygen/html"
         "$WM_PROJECT_DIR/doc/Doxygen/html"
     );
-    doxySourceFileExt "_8C.html";
+    doxySourceFileExts
+    (
+        "App_8C.html"
+        "_8C.html"
+    );
 }
 
 DebugSwitches

src/OpenFOAM/global/argList/argList.C

@@ -607,15 +607,16 @@ void Foam::argList::displayDoc() const
 {
     const dictionary& docDict = debug::controlDict().subDict("Documentation");
     List<fileName> docDirs(docDict.lookup("doxyDocDirs"));
+    List<fileName> docExts(docDict.lookup("doxySourceFileExts"));
 
     fileName docFile;
     bool found = false;
 
     forAll(docDirs, dirI)
     {
-        docFile =
-            fileName(docDirs[dirI])/executable()
-          + fileName(docDict.lookup("doxySourceFileExt"));
+        forAll(docExts, extI)
+        {
+            docFile = docDirs[dirI]/executable() + docExts[extI];
             docFile.expand();
 
             if (exists(docFile))
@@ -624,10 +625,15 @@ void Foam::argList::displayDoc() const
                 break;
             }
         }
+        if (found)
+        {
+            break;
+        }
+    }
 
     if (found)
     {
-        string docBrowser = docDict.lookup("docBrowser");
+        string docBrowser(docDict.lookup("docBrowser"));
         docBrowser.replaceAll("%f", docFile);
 
         Info<< "Show documentation: " << docBrowser.c_str() << endl;