Add function modified() to select nodes which are marked as dirty

src/augeas.c

@@ -61,6 +61,7 @@ static const char *const static_nodes[][2] = {
     { AUGEAS_META_PATHX_FUNC "/glob", NULL },
     { AUGEAS_META_PATHX_FUNC "/label", NULL },
     { AUGEAS_META_PATHX_FUNC "/last", NULL },
+    { AUGEAS_META_PATHX_FUNC "/modified", NULL },
     { AUGEAS_META_PATHX_FUNC "/position", NULL },
     { AUGEAS_META_PATHX_FUNC "/regexp", NULL }
 };
@@ -84,18 +85,21 @@ static const char *const errcodes[] = {
 };
 
 static void tree_mark_dirty(struct tree *tree) {
-    do {
-        tree->dirty = 1;
-        tree = tree->parent;
-    } while (tree != tree->parent && !tree->dirty);
     tree->dirty = 1;
+    while (tree != tree->parent ) {
+        if ( tree->file ) {
+           tree->dirty = 1;
+           break;
+        }
+        tree = tree->parent;
+    }
 }
 
 void tree_clean(struct tree *tree) {
-    if (tree->dirty) {
-        list_for_each(c, tree->children)
-            tree_clean(c);
-    }
+    if ( tree->file && ! tree->dirty )
+        return;
+    list_for_each(c, tree->children)
+        tree_clean(c);
     tree->dirty = 0;
 }
 
@@ -691,10 +695,9 @@ static void tree_mark_files(struct tree *tree) {
 static void tree_rm_dirty_files(struct augeas *aug, struct tree *tree) {
     struct tree *p;
 
-    if (!tree->dirty)
+    if (tree->file && !tree->dirty) {
         return;
-
-    if (tree->file && ((p = tree_child(tree, "path")) != NULL)) {
+    } else if (tree->file && tree->dirty && ((p = tree_child(tree, "path")) != NULL)) {
         tree_unlink(aug, tree_fpath(aug, p->value));
         tree_unlink(aug, tree);
     } else {
@@ -709,7 +712,7 @@ static void tree_rm_dirty_files(struct augeas *aug, struct tree *tree) {
 
 static void tree_rm_dirty_leaves(struct augeas *aug, struct tree *tree,
                                  struct tree *protect) {
-    if (! tree->dirty)
+    if (tree->file && !tree->dirty)
         return;
 
     struct tree *c = tree->children;
@@ -1491,19 +1494,23 @@ static int tree_save(struct augeas *aug, struct tree *tree,
         return -1;
 
     list_for_each(t, tree) {
-        if (t->dirty) {
+        if (t->file && ! t->dirty) {
+            continue;
+        } else {
             char *tpath = NULL;
             struct tree *transform = NULL;
             if (asprintf(&tpath, "%s/%s", path, t->label) == -1) {
                 result = -1;
                 continue;
             }
-            list_for_each(xfm, load->children) {
-                if (transform_applies(xfm, tpath)) {
-                    if (transform == NULL || transform == xfm) {
-                        transform = xfm;
-                    } else {
-                        result = check_save_dup(aug, tpath, transform, xfm);
+            if ( t->dirty ) {
+                list_for_each(xfm, load->children) {
+                    if (transform_applies(xfm, tpath)) {
+                        if (transform == NULL || transform == xfm) {
+                            transform = xfm;
+                        } else {
+                            result = check_save_dup(aug, tpath, transform, xfm);
+                        }
                     }
                 }
             }
@@ -1554,7 +1561,7 @@ static int unlink_removed_files(struct augeas *aug,
 
     int result = 0;
 
-    if (! files->dirty)
+    if (files->file)
         return 0;
 
     for (struct tree *tm = meta->children; tm != NULL;) {
@@ -1576,7 +1583,7 @@ static int unlink_removed_files(struct augeas *aug,
                     result = -1;
             }
             free_pathx(px);
-        } else if (tf->dirty && ! tree_child(tm, "path")) {
+        } else if (! tree_child(tm, "path")) {
             if (unlink_removed_files(aug, tf, tm) < 0)
                 result = -1;
         }
@@ -1605,15 +1612,13 @@ int aug_save(struct augeas *aug) {
     list_for_each(xfm, load->children)
         transform_validate(aug, xfm);
 
-    if (files->dirty) {
-        if (tree_save(aug, files->children, AUGEAS_FILES_TREE) == -1)
-            ret = -1;
+    if (tree_save(aug, files->children, AUGEAS_FILES_TREE) == -1)
+        ret = -1;
 
-        /* Remove files whose entire subtree was removed. */
-        if (meta_files != NULL) {
-            if (unlink_removed_files(aug, files, meta_files) < 0)
-                ret = -1;
-        }
+    /* Remove files whose entire subtree was removed. */
+    if (meta_files != NULL) {
+        if (unlink_removed_files(aug, files, meta_files) < 0)
+            ret = -1;
     }
     if (!(aug->flags & AUG_SAVE_NOOP)) {
         tree_clean(aug->origin);

src/pathx.c

@@ -300,6 +300,7 @@ static void func_regexp_flag(struct state *state, int nargs);
 static void func_glob(struct state *state, int nargs);
 static void func_int(struct state *state, int nargs);
 static void func_not(struct state *state, int nargs);
+static void func_modified(struct state *state, int nargs);
 
 static const enum type arg_types_nodeset[] = { T_NODESET };
 static const enum type arg_types_string[] = { T_STRING };
@@ -341,6 +342,8 @@ static const struct func builtin_funcs[] = {
       .arg_types = arg_types_nodeset, .impl = func_int, .pure = false },
     { .name = "int", .arity = 1, .type = T_NUMBER,
       .arg_types = arg_types_bool, .impl = func_int, .pure = false },
+    { .name = "modified", .arity = 0, .type = T_BOOLEAN,
+      .arg_types = NULL, .impl = func_modified, .pure = false },
     { .name = "not", .arity = 1, .type = T_BOOLEAN,
       .arg_types = arg_types_bool, .impl = func_not, .pure = true }
 };
@@ -724,6 +727,12 @@ static void func_int(struct state *state, int nargs) {
     push_value(vind, state);
 }
 
+static void func_modified(struct state *state, int nargs) {
+    ensure_arity(0, 0);
+
+    push_boolean_value(state->ctx->dirty , state);
+}
+
 static void func_not(struct state *state, int nargs) {
     ensure_arity(1, 1);
     RET_ON_ERROR;

tests/Makefile.am

@@ -280,7 +280,8 @@ check_SCRIPTS = \
   test-save-empty.sh test-bug-1.sh test-idempotent.sh test-preserve.sh \
   test-events-saved.sh test-save-mode.sh test-unlink-error.sh \
   test-augtool-empty-line.sh test-augtool-modify-root.sh \
-  test-span-rec-lens.sh test-nonwritable.sh test-augmatch.sh
+  test-span-rec-lens.sh test-nonwritable.sh test-augmatch.sh \
+  test-function-modified.sh
 
 EXTRA_DIST = \
   test-augtool root lens-test-1 \

tests/test-function-modified.sh

@@ -0,0 +1,47 @@
+#!/bin/sh
+
+# Test that changing the value of a node causes the function modified() to return true
+
+root=$abs_top_builddir/build/test-function-modified
+hosts=$root/etc/hosts
+
+rm -rf $root
+mkdir -p $(dirname $hosts)
+
+cat <<EOF > $hosts
+127.0.0.1 localhost
+::1       localhost6
+EOF
+
+touch -r $0 $hosts
+
+augtool --nostdinc -r $root -I $abs_top_srcdir/lenses > /dev/null <<EOF >$root/output.1
+set /files/etc/hosts/1/ipaddr 127.0.0.4
+match /files/etc/hosts//*[modified()]
+EOF
+
+[ "$(cat $root/output.1)" = '/files/etc/hosts/1/ipaddr = 127.0.0.4' ] || exit 1
+
+# An empty value should return true, even if none of the child nodes are modified
+augtool --nostdinc -r $root -I $abs_top_srcdir/lenses > /dev/null <<EOF >$root/output.2
+set /files/etc/hosts/1 x
+set /files/etc/hosts/1
+match /files/etc/hosts//*[modified()]
+EOF
+
+[ "$(cat $root/output.2)" = '/files/etc/hosts/1 = (none)' ] || exit 1
+
+# Test that changing a value does not change the parent node
+# Test that adding a new node also marks the (new) parent node.
+augtool --nostdinc -r $root -I $abs_top_srcdir/lenses > /dev/null <<EOF >$root/output.3
+set /files/etc/hosts/1/ipaddr 127.1.1.1
+set /files/etc/hosts/3/ipaddr 127.3.3.3
+match /files/etc/hosts//*[modified()]
+EOF
+
+diff -q $root/output.3  -  <<EOF || exit 1
+/files/etc/hosts/3 = (none)
+/files/etc/hosts/1/ipaddr = 127.1.1.1
+/files/etc/hosts/3/ipaddr = 127.3.3.3
+EOF
+