54676: preserve COLUMNS + LINES from the environment

3 files changed, 24 insertions, 2 deletions

diff --git a/Src/init.c b/Src/init.c
index eb34b4cab..f36bc332b 100644
--- a/Src/init.c
+++ b/Src/init.c
@@ -1288,6 +1288,23 @@ setupvals(char *cmd, char *runscript, char *zsh_name)
     condtab = NULL;
     wrappers = NULL;
 
+    zterm_columns_preserve = zterm_lines_preserve = 0;
+
+    // preserve COLUMNS and LINES from environment when non-interactive
+    if (!isset(INTERACTIVE)) {
+	char *e, *p;
+	zlong v;
+
+	if ((e = zgetenv("COLUMNS")) && (v = zstrtol(e, &p, 10)) > 0 && !*p) {
+	    zterm_columns = v;
+	    zterm_columns_preserve = 1;
+	}
+	if ((e = zgetenv("LINES")) && (v = zstrtol(e, &p, 10)) > 0 && !*p) {
+	    zterm_lines = v;
+	    zterm_lines_preserve = 1;
+	}
+    }
+
 #ifdef TIOCGWINSZ
     adjustwinsize(0);
 #else
diff --git a/Src/params.c b/Src/params.c
index 7b55d38f2..05efd19c0 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -107,6 +107,11 @@ mod_export zlong
      ppid,		/* $PPID        */
      zsh_subshell;	/* $ZSH_SUBSHELL */
 
+// whether COLUMNS and LINES should be preserved because they were imported from
+// the environment into a non-interactive shell
+/**/
+mod_export int zterm_columns_preserve, zterm_lines_preserve;
+
 /* $FUNCNEST    */
 /**/
 mod_export
diff --git a/Src/utils.c b/Src/utils.c
index 801dabd9b..0b4bb9a82 100644
--- a/Src/utils.c
+++ b/Src/utils.c
@@ -1837,7 +1837,7 @@ adjustlines(int signalled)
     int oldlines = zterm_lines;
 
 #ifdef TIOCGWINSZ
-    if (signalled || zterm_lines <= 0)
+    if ((signalled && !zterm_lines_preserve) || zterm_lines <= 0)
 	zterm_lines = shttyinfo.winsize.ws_row;
     else
 	shttyinfo.winsize.ws_row = zterm_lines;
@@ -1862,7 +1862,7 @@ adjustcolumns(int signalled)
     int oldcolumns = zterm_columns;
 
 #ifdef TIOCGWINSZ
-    if (signalled || zterm_columns <= 0)
+    if ((signalled && !zterm_columns_preserve) || zterm_columns <= 0)
 	zterm_columns = shttyinfo.winsize.ws_col;
     else
 	shttyinfo.winsize.ws_col = zterm_columns;