Revert "removed GNU extension from JSON"

This reverts commit cd6b630.

Author: WillAyd

pandas/_libs/src/ujson/lib/ultrajsondec.c

@@ -1154,6 +1154,7 @@ JSOBJ JSON_DecodeObject(JSONObjectDecoder *dec, const char *buffer,
     /*
     FIXME: Base the size of escBuffer of that of cbBuffer so that the unicode
     escaping doesn't run into the wall each time */
+    char *locale;
     struct DecoderState ds;
     wchar_t escBuffer[(JSON_MAX_STACK_BUFFER_SIZE / sizeof(wchar_t))];
     JSOBJ ret;
@@ -1172,7 +1173,19 @@ JSOBJ JSON_DecodeObject(JSONObjectDecoder *dec, const char *buffer,
 
     ds.dec = dec;
 
-    ret = decode_any(&ds);
+    locale = setlocale(LC_NUMERIC, NULL);
+    if (strcmp(locale, "C")) {
+        locale = strdup(locale);
+        if (!locale) {
+            return SetError(&ds, -1, "Could not reserve memory block");
+        }
+        setlocale(LC_NUMERIC, "C");
+        ret = decode_any(&ds);
+        setlocale(LC_NUMERIC, locale);
+        free(locale);
+    } else {
+        ret = decode_any(&ds);
+    }
 
     if (ds.escHeap) {
         dec->free(ds.escStart);

pandas/_libs/src/ujson/lib/ultrajsonenc.c

@@ -1142,6 +1142,7 @@ void encode(JSOBJ obj, JSONObjectEncoder *enc, const char *name,
 
 char *JSON_EncodeObject(JSOBJ obj, JSONObjectEncoder *enc, char *_buffer,
                         size_t _cbBuffer) {
+    char *locale;
     enc->malloc = enc->malloc ? enc->malloc : malloc;
     enc->free = enc->free ? enc->free : free;
     enc->realloc = enc->realloc ? enc->realloc : realloc;
@@ -1174,7 +1175,20 @@ char *JSON_EncodeObject(JSOBJ obj, JSONObjectEncoder *enc, char *_buffer,
     enc->end = enc->start + _cbBuffer;
     enc->offset = enc->start;
 
-    encode(obj, enc, NULL, 0);
+    locale = setlocale(LC_NUMERIC, NULL);
+    if (strcmp(locale, "C")) {
+        locale = strdup(locale);
+        if (!locale) {
+            SetError(NULL, enc, "Could not reserve memory block");
+            return NULL;
+        }
+        setlocale(LC_NUMERIC, "C");
+        encode(obj, enc, NULL, 0);
+        setlocale(LC_NUMERIC, locale);
+        free(locale);
+    } else {
+        encode(obj, enc, NULL, 0);
+    }
 
     Buffer_Reserve(enc, 1);
     if (enc->errorMsg) {

setup.py

@@ -649,7 +649,7 @@ def srcpath(name=None, suffix=".pyx", subdir="src"):
         "pandas/_libs/src/datetime",
         numpy.get_include(),
     ],
-    extra_compile_args=(extra_compile_args),
+    extra_compile_args=(["-D_GNU_SOURCE"] + extra_compile_args),
     extra_link_args=extra_link_args,
     define_macros=macros,
 )