vim-patch:7.4.831

Problem:    When expanding `=expr` on the command line and encountering an
            error, the command is executed anyway.
Solution:   Bail out when an error is detected.

3f188935ec

src/nvim/path.c

@@ -1117,6 +1117,7 @@ int gen_expand_wildcards(int num_pat, char_u **pat, int *num_file,
   char_u              *p;
   static bool recursive = false;
   int add_pat;
+  bool retval = OK;
   bool did_expand_in_path = false;
 
   /*
@@ -1158,12 +1159,13 @@ int gen_expand_wildcards(int num_pat, char_u **pat, int *num_file,
     add_pat = -1;
     p = pat[i];
 
-    if (vim_backtick(p))
+    if (vim_backtick(p)) {
       add_pat = expand_backtick(&ga, p, flags);
-    else {
+      if (add_pat == -1) {
-      /*
+        retval = FAIL;
-       * First expand environment variables, "~/" and "~user/".
+      }
-       */
+    } else {
+      // First expand environment variables, "~/" and "~user/".
       if (has_env_var(p) || *p == '~') {
         p = expand_env_save_opt(p, true);
         if (p == NULL)
@@ -1234,7 +1236,7 @@ int gen_expand_wildcards(int num_pat, char_u **pat, int *num_file,
 
   recursive = false;
 
-  return (ga.ga_data != NULL) ? OK : FAIL;
+  return (ga.ga_data != NULL) ? retval : FAIL;
 }
 
 
@@ -1246,13 +1248,10 @@ static int vim_backtick(char_u *p)
   return *p == '`' && *(p + 1) != NUL && *(p + STRLEN(p) - 1) == '`';
 }
 
-/*
+// Expand an item in `backticks` by executing it as a command.
- * Expand an item in `backticks` by executing it as a command.
+// Currently only works when pat[] starts and ends with a `.
- * Currently only works when pat[] starts and ends with a `.
+// Returns number of file names found, -1 if an error is encountered.
- * Returns number of file names found.
+static int expand_backtick(
- */
-static int 
-expand_backtick (
     garray_T *gap,
     char_u *pat,
     int flags              /* EW_* flags */
@@ -1273,8 +1272,9 @@ expand_backtick (
     buffer = get_cmd_output(cmd, NULL,
         (flags & EW_SILENT) ? kShellOptSilent : 0, NULL);
   xfree(cmd);
-  if (buffer == NULL)
+  if (buffer == NULL) {
-    return 0;
+    return -1;
+  }
 
   cmd = buffer;
   while (*cmd != NUL) {

src/nvim/version.c

@@ -459,7 +459,7 @@ static int included_patches[] = {
   834,
   833,
   // 832,
-  // 831,
+  831,
   830,
   // 829 NA
   828,