Fix --nul-output option to abort on a string containing NUL

jqlang · Jul 22, 2023 · 86699b4 · 86699b4
1 parent e0e1b22
commit 86699b4
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Showing 3 changed files with 20 additions and 2 deletions.
diff --git a/docs/content/manual/manual.yml b/docs/content/manual/manual.yml
@@ -213,6 +213,7 @@ sections:
 
         Like `-r` but jq will print NUL instead of newline after each output.
         This can be useful when the values being output can contain newlines.
+        When the output value contains NUL, jq exits with non-zero code.
 
       * `-f filename` / `--from-file filename`:
 

diff --git a/src/main.c b/src/main.c
@@ -181,11 +181,18 @@ static int process(jq_state *jq, jv value, int flags, int dumpopts, int options)
     if ((options & RAW_OUTPUT) && jv_get_kind(result) == JV_KIND_STRING) {
       if (options & ASCII_OUTPUT) {
         jv_dumpf(jv_copy(result), stdout, JV_PRINT_ASCII);
+        ret = JQ_OK;
+      } else if ((options & RAW_NUL) && strlen(jv_string_value(result)) != (unsigned long)jv_string_length_bytes(jv_copy(result))) {
+        jv input_pos = jq_util_input_get_position(jq);
+        fprintf(stderr, "jq: error (at %s): %s\n",
+            jv_string_value(input_pos), "Cannot dump a string containing NUL with --nul-output option");
+        jv_free(input_pos);
+        ret = JQ_ERROR_UNKNOWN;
       } else {
         priv_fwrite(jv_string_value(result), jv_string_length_bytes(jv_copy(result)),
             stdout, dumpopts & JV_PRINT_ISATTY);
+        ret = JQ_OK;
       }
-      ret = JQ_OK;
       jv_free(result);
     } else {
       if (jv_get_kind(result) == JV_KIND_FALSE || jv_get_kind(result) == JV_KIND_NULL)
@@ -198,7 +205,7 @@ static int process(jq_state *jq, jv value, int flags, int dumpopts, int options)
     }
     if (!(options & RAW_NO_LF))
       priv_fwrite("\n", 1, stdout, dumpopts & JV_PRINT_ISATTY);
-    if (options & RAW_NUL)
+    if ((options & RAW_NUL) && ret != JQ_ERROR_UNKNOWN)
       priv_fwrite("\0", 1, stdout, dumpopts & JV_PRINT_ISATTY);
     if (options & UNBUFFERED_OUTPUT)
       fflush(stdout);

diff --git a/tests/shtest b/tests/shtest
@@ -171,6 +171,16 @@ printf '["a", "b"]' | $JQ -0 .[] > $d/out 2>&1
 cmp $d/out $d/expected
 printf '["a", "b"]' | $JQ --nul-output .[] > $d/out 2>&1
 cmp $d/out $d/expected
+printf '["a", "c\\u0000d", "b"]' | $JQ --nul-output .[] > $d/out 2>/dev/null
+cmp $d/out $d/expected
+
+if printf '{"foo":"foo\\u0000bar"}' | $JQ --nul-output .foo; then
+  echo "Should exit error on string containing NUL with --nul-output" 1>&2
+  exit 1
+elif [ $? -ne 5 ]; then
+  echo "Invalid error code" 1>&2
+  exit 1
+fi
 
 ## Test streaming parser