--- a/include/ap_regex.h	2018/02/16 13:26:45	1824471
+++ b/include/ap_regex.h	2018/02/16 13:27:44	1824472
@@ -77,6 +77,8 @@
 #define AP_REG_NOMEM 0x20    /* nomem in our code */
 #define AP_REG_DOTALL 0x40   /* perl's /s flag */
 
+#define AP_REG_DOLLAR_ENDONLY 0x200 /* '$' matches at end of subject string only */
+
 #define AP_REG_MATCH "MATCH_" /** suggested prefix for ap_regname */
 
 /* Error values: */
@@ -103,6 +105,26 @@
 /* The functions */
 
 /**
+ * Get default compile flags
+ * @return Bitwise OR of AP_REG_* flags
+ */
+AP_DECLARE(int) ap_regcomp_get_default_cflags(void);
+
+/**
+ * Set default compile flags
+ * @param cflags Bitwise OR of AP_REG_* flags
+ */
+AP_DECLARE(void) ap_regcomp_set_default_cflags(int cflags);
+
+/**
+ * Get the AP_REG_* corresponding to the string.
+ * @param name The name (i.e. AP_REG_<name>)
+ * @return The AP_REG_*, or zero if the string is unknown
+ *
+ */
+AP_DECLARE(int) ap_regcomp_default_cflag_by_name(const char *name);
+
+/**
  * Compile a regular expression.
  * @param preg Returned compiled regex
  * @param regex The regular expression string
--- a/server/core.c	2018/02/16 13:26:45	1824471
+++ b/server/core.c	2018/02/16 13:27:44	1824472
@@ -48,6 +48,7 @@
 #include "mod_core.h"
 #include "mod_proxy.h"
 #include "ap_listen.h"
+#include "ap_regex.h"
 
 #include "mod_so.h" /* for ap_find_loaded_module_symbol */
 
@@ -2847,6 +2848,58 @@
     return errmsg;
 }
 
+static const char *set_regex_default_options(cmd_parms *cmd,
+                                             void *dummy,
+                                             const char *arg)
+{
+    const command_rec *thiscmd = cmd->cmd;
+    int cflags, cflag;
+
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    if (err != NULL) {
+        return err;
+    }
+
+    cflags = ap_regcomp_get_default_cflags();
+    while (*arg) {
+        const char *name = ap_getword_conf(cmd->pool, &arg);
+        int how = 0;
+
+        if (strcasecmp(name, "none") == 0) {
+            cflags = 0;
+            continue;
+        }
+
+        if (*name == '+') {
+            name++;
+            how = +1;
+        }
+        else if (*name == '-') {
+            name++;
+            how = -1;
+        }
+
+        cflag = ap_regcomp_default_cflag_by_name(name);
+        if (!cflag) {
+            return apr_psprintf(cmd->pool, "%s: option '%s' unknown",
+                                thiscmd->name, name);
+        }
+
+        if (how > 0) {
+            cflags |= cflag;
+        }
+        else if (how < 0) {
+            cflags &= ~cflag;
+        }
+        else {
+            cflags = cflag;
+        }
+    }
+    ap_regcomp_set_default_cflags(cflags);
+
+    return NULL;
+}
+
 static const char *set_server_alias(cmd_parms *cmd, void *dummy,
                                     const char *arg)
 {
@@ -4421,6 +4474,9 @@
    OR_ALL, "soft/hard limits for max number of processes per uid"),
 #endif
 
+AP_INIT_RAW_ARGS("RegexDefaultOptions", set_regex_default_options, NULL, RSRC_CONF,
+                 "default options for regexes (prefixed by '+' to add, '-' to del)"),
+
 /* internal recursion stopper */
 AP_INIT_TAKE12("LimitInternalRecursion", set_recursion_limit, NULL, RSRC_CONF,
               "maximum recursion depth of internal redirects and subrequests"),
@@ -4856,6 +4912,8 @@
     apr_pool_cleanup_register(pconf, NULL, reset_config_defines,
                               apr_pool_cleanup_null);
 
+    ap_regcomp_set_default_cflags(AP_REG_DOLLAR_ENDONLY);
+
     mpm_common_pre_config(pconf);
 
     return OK;
--- a/server/util_pcre.c	2018/02/16 13:26:45	1824471
+++ b/server/util_pcre.c	2018/02/16 13:27:44	1824472
@@ -111,6 +111,38 @@
  *            Compile a regular expression       *
  *************************************************/
 
+static int default_cflags = AP_REG_DOLLAR_ENDONLY;
+
+AP_DECLARE(int) ap_regcomp_get_default_cflags(void)
+{
+    return default_cflags;
+}
+
+AP_DECLARE(void) ap_regcomp_set_default_cflags(int cflags)
+{
+    default_cflags = cflags;
+}
+
+AP_DECLARE(int) ap_regcomp_default_cflag_by_name(const char *name)
+{
+    int cflag = 0;
+
+    if (ap_cstr_casecmp(name, "ICASE") == 0) {
+        cflag = AP_REG_ICASE;
+    }
+    else if (ap_cstr_casecmp(name, "DOTALL") == 0) {
+        cflag = AP_REG_DOTALL;
+    }
+    else if (ap_cstr_casecmp(name, "DOLLAR_ENDONLY") == 0) {
+        cflag = AP_REG_DOLLAR_ENDONLY;
+    }
+    else if (ap_cstr_casecmp(name, "EXTENDED") == 0) {
+        cflag = AP_REG_EXTENDED;
+    }
+
+    return cflag;
+}
+
 /*
  * Arguments:
  *  preg        points to a structure for recording the compiled expression
@@ -127,12 +159,15 @@
     int errcode = 0;
     int options = PCRE_DUPNAMES;
 
+    cflags |= default_cflags;
     if ((cflags & AP_REG_ICASE) != 0)
         options |= PCRE_CASELESS;
     if ((cflags & AP_REG_NEWLINE) != 0)
         options |= PCRE_MULTILINE;
     if ((cflags & AP_REG_DOTALL) != 0)
         options |= PCRE_DOTALL;
+    if ((cflags & AP_REG_DOLLAR_ENDONLY) != 0)
+        options |= PCRE_DOLLAR_ENDONLY;
 
     preg->re_pcre =
         pcre_compile2(pattern, options, &errcode, &errorptr, &erroffset, NULL);
