Fix WKTWriter for small precisions and with trim enabled

libgeos · Nov 20, 2024 · dac7f97 · dac7f97
1 parent 9687512
commit dac7f97
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/src/io/WKTWriter.cpp b/src/io/WKTWriter.cpp
@@ -460,7 +460,10 @@ WKTWriter::writeTrimmedNumber(double d, uint32_t precision, char* buf)
         // most real-world coordinates, use positional notation
         if ( (precision < 4) && (da < 1.0) ) {
             // adjust precision to avoid rounding to zero
-            precision = static_cast<std::uint32_t>(-floor(log10(da)));
+            const auto higher_prec = static_cast<std::uint32_t>(-floor(log10(da)));
+            if (higher_prec > precision) {
+                precision = higher_prec;
+            }
         }
         return geos_d2sfixed_buffered_n(d, precision, buf);
     }

diff --git a/tests/unit/capi/GEOS_printDoubleTest.cpp b/tests/unit/capi/GEOS_printDoubleTest.cpp
@@ -69,6 +69,21 @@ void object::test<1>()
         TESTCASE(12, 1.2345678901234e+17, "1.234567890123e+17"),
         TESTCASE(13, 1.2345678901234e+17, "1.2345678901234e+17"),
         TESTCASE(14, 1.2345678901234e+17, "1.2345678901234e+17"),
+        TESTCASE(0, 0.0123456789, "0.01"),
+        TESTCASE(1, 0.0123456789, "0.01"),
+        TESTCASE(2, 0.0123456789, "0.01"),
+        TESTCASE(3, 0.0123456789, "0.012"),
+        TESTCASE(4, 0.0123456789, "0.0123"),
+        TESTCASE(0, 0.123456789, "0.1"),
+        TESTCASE(1, 0.123456789, "0.1"),
+        TESTCASE(2, 0.123456789, "0.12"),
+        TESTCASE(3, 0.123456789, "0.123"),
+        TESTCASE(4, 0.123456789, "0.1235"),
+        TESTCASE(0, 1.23456789, "1"),
+        TESTCASE(1, 1.23456789, "1.2"),
+        TESTCASE(2, 1.23456789, "1.23"),
+        TESTCASE(3, 1.23456789, "1.235"),
+        TESTCASE(4, 1.23456789, "1.2346"),
     };
     for (const auto& testcase : testcase_l) {
         char buf[28];