InputScalar: fixed not parsing user input when the display format is configured not to show the scalar value. (#9385)

Useful e.g. for displaying "mixed" inputs, where a single field might represent multiple different values.

docs/CHANGELOG.txt

diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 5b12ba4..dce8025 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -97,6 +97,8 @@
     with 1.91.4 behavior.
   - In a majority of cases you should use IsItemDeactivatedAfterEdit() instead,
     but it still has a few edge cases flaws (to be addressed soon).
+- InputInt, InputFloat, InputScalar: allow passing a format string that does not display
+  the scalar value. Parsing input with default format for the type. (#9385) [@FireFox2000000]
 - Multi-Select:
   - Fixed an issue using Multi-Select within a Table causing column width measurement to
     be invalid when trailing column contents is not submitted in the last row. (#9341, #8250)

imgui_widgets.cpp

diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index ecad830..d05857d 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -2375,12 +2375,17 @@
 
     // Sanitize format
     // - For float/double we have to ignore format with precision (e.g. "%.2f") because sscanf doesn't take them in, so force them into %f and %lf
-    // - In theory could treat empty format as using default, but this would only cover rare/bizarre case of using InputScalar() + integer + format string without %.
     char format_sanitized[32];
     if (data_type == ImGuiDataType_Float || data_type == ImGuiDataType_Double)
+    {
         format = type_info->ScanFmt;
+    }
     else
+    {
         format = ImParseFormatSanitizeForScanning(format, format_sanitized, IM_COUNTOF(format_sanitized));
+        if (format[0] == '\0')
+            format = type_info->ScanFmt; // Format doesn't want us to show the number currently, but we still need to parse the resulting input
+    }
 
     // Small types need a 32-bit buffer to receive the result from scanf()
     int v32 = 0;