From bcd23743f4f9e0182b63c6ac565d5f1eb467bcbb Mon Sep 17 00:00:00 2001
From: Ladislav Michl <ladis@triops.cz>
Date: Tue, 27 May 2025 12:08:05 +0200
Subject: [PATCH] Base: fix UnitsSchema::translate

Schema translation previously returned factor 0 and unit string
of input quantity if there was no translation match. Restore
that behaviour as well as returned factor and unit string of
imperial schemas.

Fixes: 1155f0d75281 ("Base: simplify UnitsSchemas management")
---
 src/Base/UnitsSchema.cpp    | 16 +++++++---------
 src/Base/UnitsSchemasData.h | 20 +++++++++++++++-----
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/src/Base/UnitsSchema.cpp b/src/Base/UnitsSchema.cpp
index 1fbc4e0169..3665ea8c2f 100644
--- a/src/Base/UnitsSchema.cpp
+++ b/src/Base/UnitsSchema.cpp
@@ -53,22 +53,20 @@ std::string UnitsSchema::translate(const Quantity& quant) const
 std::string
 UnitsSchema::translate(const Quantity& quant, double& factor, std::string& unitString) const
 {
+    // Use defaults without schema-level translation.
+    factor = 1.0;
+    unitString = quant.getUnit().getString();
+
     if (spec.translationSpecs.empty()) {
-        return toLocale(quant, 1.0, unitString);
+        return toLocale(quant, factor, unitString);
     }
 
     const auto unitName = quant.getUnit().getTypeString();
-
-    if (spec.translationSpecs.count(unitName) == 0) {
-        // no schema-level translation. Use defaults.
-        factor = 1.0;
-        unitString = quant.getUnit().getString();
-
+    if (!spec.translationSpecs.contains(unitName)) {
         return toLocale(quant, factor, unitString);
     }
 
     const auto value = quant.getValue();
-
     auto isSuitable = [&](const UnitTranslationSpec& row) {
         return row.threshold > value || row.threshold == 0;  // zero indicates default
     };
@@ -81,7 +79,7 @@ UnitsSchema::translate(const Quantity& quant, double& factor, std::string& unitS
     }
 
     if (unitSpec->factor == 0) {
-        return UnitsSchemasData::runSpecial(unitSpec->unitString, value);
+        return UnitsSchemasData::runSpecial(unitSpec->unitString, value, factor, unitString);
     }
 
     factor = unitSpec->factor;
diff --git a/src/Base/UnitsSchemasData.h b/src/Base/UnitsSchemasData.h
index 8f937c1a50..45f25bdc98 100644
--- a/src/Base/UnitsSchemasData.h
+++ b/src/Base/UnitsSchemasData.h
@@ -733,17 +733,27 @@ inline std::string toDms(const double value)
  * Special functions caller
  */
 
-inline const std::map<std::string, std::function<std::string(double)>> specials  // clang-format off
+// clang-format off
+inline const std::map<std::string, std::function<std::string(double, double&, std::string&)>> specials
 {
     {
-        { "toDMS"        , [](const double val) { return toDms(val);        }},
-        { "toFractional" , [](const double val) { return toFractional(val); }}
+        { "toDMS"        , [](const double val, double& factor, std::string& unitString) {
+            factor = 1.0;
+            unitString = "deg";
+            return toDms(val);
+        }},
+        { "toFractional" , [](const double val, double& factor, std::string& unitString) {
+            factor = 25.4;
+            unitString = "in";
+            return toFractional(val);
+        }}
     }
 };  // clang-format on
 
-inline std::string runSpecial(const std::string& name, const double value)
+inline std::string
+runSpecial(const std::string& name, const double value, double& factor, std::string& unitString)
 {
-    return specials.contains(name) ? specials.at(name)(value) : "";
+    return specials.contains(name) ? specials.at(name)(value, factor, unitString) : "";
 }