patch 8.0.0829: job running in terminal can't communicate with Vim

Problem:    A job running in a terminal window cannot easily communicate with
            the Vim it is running in.
Solution:   Pass v:servername in an environment variable. (closes #1908)

Author: brammool

src/os_unix.c

@@ -4094,6 +4094,9 @@ mch_parse_cmd(char_u *cmd, int use_shcf, char ***argv, int *argc)
 #endif
 
 #if !defined(USE_SYSTEM) || defined(FEAT_JOB_CHANNEL)
+/*
+ * Set the environment for a child process.
+ */
     static void
 set_child_environment(long rows, long columns, char *term)
 {
@@ -4105,14 +4108,14 @@ set_child_environment(long rows, long columns, char *term)
     static char	envbuf_Lines[20];
     static char	envbuf_Columns[20];
     static char	envbuf_Colors[20];
+    static char	envbuf_Servername[60];
 # endif
     long	colors =
 #  ifdef FEAT_GUI
 	    gui.in_use ? 256*256*256 :
 #  endif
 	    t_colors;
 
-    /* Simulate to have a dumb terminal (for now) */
 # ifdef HAVE_SETENV
     setenv("TERM", term, 1);
     sprintf((char *)envbuf, "%ld", rows);
@@ -4123,10 +4126,12 @@ set_child_environment(long rows, long columns, char *term)
     setenv("COLUMNS", (char *)envbuf, 1);
     sprintf((char *)envbuf, "%ld", colors);
     setenv("COLORS", (char *)envbuf, 1);
+    setenv("VIM_SERVERNAME", serverName == NULL ? "" : (char *)serverName, 1);
 # else
     /*
      * Putenv does not copy the string, it has to remain valid.
      * Use a static array to avoid losing allocated memory.
+     * This won't work well when running multiple children...
      */
     vim_snprintf(envbuf_Term, sizeof(envbuf_Term), "TERM=%s", term);
     putenv(envbuf_Term);
@@ -4139,6 +4144,9 @@ set_child_environment(long rows, long columns, char *term)
     putenv(envbuf_Columns);
     vim_snprintf(envbuf_Colors, sizeof(envbuf_Colors), "COLORS=%ld", colors);
     putenv(envbuf_Colors);
+    vim_snprintf(envbuf_Servername, sizeof(envbuf_Servername),
+	    "VIM_SERVERNAME=%s", serverName == NULL ? "" : (char *)serverName);
+    putenv(envbuf_Servername);
 # endif
 }
 

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    829,
 /**/
     828,
 /**/