diff --git a/src/applications/search/compiler/PhutilSearchQueryCompiler.php b/src/applications/search/compiler/PhutilSearchQueryCompiler.php
--- a/src/applications/search/compiler/PhutilSearchQueryCompiler.php
+++ b/src/applications/search/compiler/PhutilSearchQueryCompiler.php
@@ -172,8 +172,10 @@
       }
 
       if ($mode == 'operator') {
-        if (preg_match('/^\s\z/u', $character)) {
-          continue;
+        if (!$current_operator) {
+          if (preg_match('/^\s\z/u', $character)) {
+            continue;
+          }
         }
 
         if (preg_match('/^'.$operator_characters.'\z/', $character)) {
@@ -337,6 +339,7 @@
         'operator' => $operator,
         'quoted' => $is_quoted,
         'value' => $value,
+        'raw' => $this->getDisplayToken($token),
       );
 
       if ($enable_functions) {
@@ -355,16 +358,58 @@
 
         $result['function'] = $function;
 
-        if ($result['quoted']) {
-          $last_function = null;
-        } else {
+        $is_sticky = !$result['quoted'];
+        switch ($operator) {
+          case self::OPERATOR_ABSENT:
+          case self::OPERATOR_PRESENT:
+            $is_sticky = false;
+            break;
+        }
+
+        if ($is_sticky) {
           $last_function = $function;
+        } else {
+          $last_function = null;
         }
       }
 
       $results[] = $result;
     }
 
+    if ($enable_functions) {
+      // If any function is required to be "absent", there must be no other
+      // terms which make assertions about it.
+
+      $present_tokens = array();
+      $absent_tokens = array();
+      foreach ($results as $result) {
+        $function = $result['function'];
+
+        if ($result['operator'] === self::OPERATOR_ABSENT) {
+          $absent_tokens[$function][] = $result;
+        } else {
+          $present_tokens[$function][] = $result;
+        }
+      }
+
+      foreach ($absent_tokens as $function => $tokens) {
+        $absent_token = head($tokens);
+
+        if (empty($present_tokens[$function])) {
+          continue;
+        }
+
+        $present_token = head($present_tokens[$function]);
+
+        throw new PhutilSearchQueryCompilerSyntaxException(
+          pht(
+            'Query field must be absent ("%s") and present ("%s"). This '.
+            'is impossible, so the query is not valid.',
+            $absent_token['raw'],
+            $present_token['raw']));
+      }
+    }
+
     return $results;
   }
 
diff --git a/src/applications/search/compiler/__tests__/PhutilSearchQueryCompilerTestCase.php b/src/applications/search/compiler/__tests__/PhutilSearchQueryCompilerTestCase.php
--- a/src/applications/search/compiler/__tests__/PhutilSearchQueryCompilerTestCase.php
+++ b/src/applications/search/compiler/__tests__/PhutilSearchQueryCompilerTestCase.php
@@ -10,10 +10,6 @@
       'cat -dog' => '+"cat" -"dog"',
       'cat-dog' => '+"cat-dog"',
 
-      // If there are spaces after an operator, the operator applies to the
-      // next search term.
-      'cat - dog' => '+"cat" -"dog"',
-
       // Double quotes serve as delimiters even if there is no whitespace
       // between terms.
       '"cat"dog' => '+"cat" +"dog"',
@@ -40,9 +36,16 @@
       // Trailing whitespace should be discarded.
       'a b ' => '+"a" +"b"',
 
-      // Functions must have search text.
+      // Tokens must have search text.
       '""' => false,
       '-' => false,
+
+      // Previously, we permitted spaces to appear inside or after operators.
+
+      // Now that "title:-" is now a valid construction meaning "title is
+      // absent", this had to be tightened. We want "title:- duck" to mean
+      // "title is absent, and any other field matches 'duck'".
+      'cat - dog' => false,
     );
 
     $this->assertCompileQueries($tests);
@@ -171,6 +174,21 @@
         array('title', $op_and, 'x'),
         array(null, $op_and, 'y'),
       ),
+
+      // The "present" and "absent" functions are not sticky.
+      'title:~ x' => array(
+        array('title', $op_present, null),
+        array(null, $op_and, 'x'),
+      ),
+      'title:- x' => array(
+        array('title', $op_absent, null),
+        array(null, $op_and, 'x'),
+      ),
+
+      // These queries require a field be both present and absent, which is
+      // impossible.
+      'title:- title:x' => false,
+      'title:- title:~' => false,
     );
 
     $this->assertCompileFunctionQueries($function_tests);