Windows has a function called GetTextMetrics that returns information about a font. This data is used by the runtime to compute the "maximum character width" and "wide character width" of a font. The "maximum width" amount is used to set a lower bound for how small an entry field can be (to ensure that at least one character is always visible). The "wide width" is used to scale small entry fields and uppercase entry fields. The "wide width" is computed by averaging the maximum and average character widths. Experimentation has shown that the "maximum character width" data returned may be inaccurate, sometimes by very large margins.

With the use of the V71_FONT_WIDTHS configuration variable, the runtime validates the data returned by the Windows function and corrects it when it is too large. The change does not affect programs until they are recompiled with Version 7.2 or later, or the change is specifically enabled through the V71_FONT_WIDTHS configuration option. The variable can have the following values:



(default) The change is enabled for programs using Version 7.2 or later semantics. In other words, the program has been compiled with Version 7.2 or later and the command line does not contain a compiler option for pre-7.2 semantics.
0 The change is enabled.
1 The change is disabled and the Version 7.1 and earlier font measuring code is used.

Note the following issues regarding the use of this variable: