diff --git a/src/box/tuple_update.c b/src/box/tuple_update.c
index 7a203ced82cf298b2c052f87517e28bb283453ff..785a88640ce2ff3fb6fe04abcb0caf86a62da940 100644
--- a/src/box/tuple_update.c
+++ b/src/box/tuple_update.c
@@ -33,6 +33,7 @@
#include <stdio.h>
#include <stdbool.h>
+#include <float.h>
#include "say.h"
#include "error.h"
@@ -484,15 +485,15 @@ make_arith_operation(struct op_arith_arg arg1, struct op_arith_arg arg2,
err_fieldno, "a positive integer");
return -1;
}
- if (lowest_type == AT_DOUBLE) {
- /* result is DOUBLE */
+ float fc = (float)c;
+ if ((lowest_type == AT_DOUBLE && c != (double) fc) ||
+ (lowest_type == AT_FLOAT &&
+ (c >= FLT_MAX || c <= -FLT_MAX))) {
ret->type = AT_DOUBLE;
ret->dbl = c;
} else {
- /* result is FLOAT */
- assert(lowest_type == AT_FLOAT);
ret->type = AT_FLOAT;
- ret->flt = (float)c;
+ ret->flt = fc;
}
}
return 0;
diff --git a/test/box/update.result b/test/box/update.result
index a3f731b55df43f5acc3ad77f1265dfd3d4b7f891..0dbe0f0a1e932f7e8472971802555acf9d69afdd 100644
--- a/test/box/update.result
+++ b/test/box/update.result
@@ -849,3 +849,68 @@ s:update(1, {{'=', 3, map}})
s:drop()
---
...
+--
+-- gh-4701: arith operations should not truncate result when
+-- float + float fits double.
+--
+msgpackffi = require('msgpackffi')
+---
+...
+mp_array_1 = 0x91
+---
+...
+mp_double = 0xcb
+---
+...
+mp_float = 0xca
+---
+...
+flt_max = 3.402823466e+38
+---
+...
+uint_max = 18446744073709551615ULL
+---
+...
+-- Double + double is float if result fits. \
+-- Double + double is double if result does not fit float. \
+-- Double + float is float if result fits. \
+-- Double + float is double if result does not fit float. \
+-- Float + float is float when no overflow. \
+-- Float + float is double when overflow. \
+-- Float + int is float when fits the float range. \
+-- Precision matters too. Double is used when need to avoid \
+-- precision loss. \
+tests = { \
+ {{'double', 1}, {'double', 1}, mp_float}, \
+ {{'double', flt_max}, {'double', flt_max}, mp_double}, \
+ {{'double', 1}, {'float', 1}, mp_float}, \
+ {{'double', flt_max}, {'float', flt_max}, mp_double}, \
+ {{'float', 1}, {'float', 1}, mp_float}, \
+ {{'float', flt_max}, {'float', flt_max}, mp_double}, \
+ {{'float', -flt_max}, {'float', -flt_max}, mp_double}, \
+ {{'float', 1}, {'int', 1}, mp_float}, \
+ {{'float', flt_max}, {'uint64_t', uint_max}, mp_double}, \
+ {{'float', 1.0001}, {'double', 1.0000000000001}, mp_double}, \
+}
+---
+...
+err = nil
+---
+...
+for i, test in pairs(tests) do \
+ local val1 = ffi.cast(test[1][1], test[1][2]) \
+ local val2 = ffi.cast(test[2][1], test[2][2]) \
+ local t = box.tuple.new({val1}) \
+ t = t:update({{'+', 1, val2}}) \
+ local m = msgpackffi.encode(t) \
+ if m:byte(1) ~= mp_array_1 or m:byte(2) ~= test[3] then \
+ err = {i, test, t, m:byte(1), m:byte(2)} \
+ break \
+ end \
+end
+---
+...
+err
+---
+- null
+...
diff --git a/test/box/update.test.lua b/test/box/update.test.lua
index c455bc1e1e112a02892c6e2c397a7adec3a519ff..724011c38fe6acc2d86cfb00adbd2d6c35893889 100644
--- a/test/box/update.test.lua
+++ b/test/box/update.test.lua
@@ -269,3 +269,48 @@ t:update({{'=', 3, map}})
s:update(1, {{'=', 3, map}})
s:drop()
+
+--
+-- gh-4701: arith operations should not truncate result when
+-- float + float fits double.
+--
+msgpackffi = require('msgpackffi')
+mp_array_1 = 0x91
+mp_double = 0xcb
+mp_float = 0xca
+flt_max = 3.402823466e+38
+uint_max = 18446744073709551615ULL
+tests = { \
+-- Double + double is float if result fits. \
+ {{'double', 1}, {'double', 1}, mp_float}, \
+-- Double + double is double if result does not fit float. \
+ {{'double', flt_max}, {'double', flt_max}, mp_double}, \
+-- Double + float is float if result fits. \
+ {{'double', 1}, {'float', 1}, mp_float}, \
+-- Double + float is double if result does not fit float. \
+ {{'double', flt_max}, {'float', flt_max}, mp_double}, \
+-- Float + float is float when no overflow. \
+ {{'float', 1}, {'float', 1}, mp_float}, \
+-- Float + float is double when overflow. \
+ {{'float', flt_max}, {'float', flt_max}, mp_double}, \
+ {{'float', -flt_max}, {'float', -flt_max}, mp_double}, \
+-- Float + int is float when fits the float range. \
+ {{'float', 1}, {'int', 1}, mp_float}, \
+ {{'float', flt_max}, {'uint64_t', uint_max}, mp_double}, \
+-- Precision matters too. Double is used when need to avoid \
+-- precision loss. \
+ {{'float', 1.0001}, {'double', 1.0000000000001}, mp_double}, \
+}
+err = nil
+for i, test in pairs(tests) do \
+ local val1 = ffi.cast(test[1][1], test[1][2]) \
+ local val2 = ffi.cast(test[2][1], test[2][2]) \
+ local t = box.tuple.new({val1}) \
+ t = t:update({{'+', 1, val2}}) \
+ local m = msgpackffi.encode(t) \
+ if m:byte(1) ~= mp_array_1 or m:byte(2) ~= test[3] then \
+ err = {i, test, t, m:byte(1), m:byte(2)} \
+ break \
+ end \
+end
+err