Don't ignore first character after a string.

The parser in QMakeSourceFileInfo::findDeps() would step over the
closing quote of a string, only to have a for loop then step over the
character just after that closing quote, which was thus never studied;
this could lead to problems in various ways.  Fixed that and expanded
findDeps() test to catch regressions.

Task-number: QTBUG-17533
Change-Id: I7dec5222e38fa188495b39376ffee70bc7bbc87f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

qmake/generators/makefiledeps.cpp

@@ -584,17 +584,14 @@ bool QMakeSourceFileInfo::findDeps(SourceFile *file)
                         // buffer[x] is '"'
                     } else {
                         const char term = buffer[x];
-                        while (++x < buffer_len) {
-                            if (buffer[x] == term) {
+                        while (++x < buffer_len && buffer[x] != term) {
+                            if (buffer[x] == '\\')
                                 ++x;
-                                break;
-                            } else if (buffer[x] == '\\') {
-                                ++x;
-                            } else if (qmake_endOfLine(buffer[x])) {
+                            else if (qmake_endOfLine(buffer[x]))
                                 ++line_count;
                         }
                     }
-                    }
+                    // for loop's ++x shall step over the closing quote.
                 }
                 beginning = 0;
             }

tests/auto/tools/qmake/testdata/findDeps/main.cpp

@@ -35,6 +35,9 @@
  / #include "needed.cpp"
 // if not ignored, symbol needed() won't be available ...
 
+// Check we're not confused by string juxtaposition:
+static const char text[] = "lorem ""ipsum /*";
+
             #include <moc_object1.cpp>
 /**/        #include <moc_object2.cpp>
 /**//**/    #include <moc_object3.cpp>