Merge branch 'jc/maint-merge-autoedit' into maint

[git.git] / pager.c

diff --git a/pager.c b/pager.c
index 4921843577e42b774457a61277b9bc3441d3ab6b..b7909678f459d90d1c8907c78bb5fcb512fe558d 100644 (file)
--- a/pager.c
+++ b/pager.c
@@ -2,14 +2,16 @@
 #include "run-command.h"
 #include "sigchain.h"
 
+#ifndef DEFAULT_PAGER
+#define DEFAULT_PAGER "less"
+#endif
+
 /*
  * This is split up from the rest of git so that we can do
  * something different on Windows.
  */
 
-static int spawned_pager;
-
-#ifndef __MINGW32__
+#ifndef WIN32
 static void pager_preexec(void)
 {
        /*
@@ -21,12 +23,10 @@ static void pager_preexec(void)
        FD_ZERO(&in);
        FD_SET(0, &in);
        select(1, &in, NULL, &in, NULL);
-
-       setenv("LESS", "FRSX", 0);
 }
 #endif
 
-static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
+static const char *pager_argv[] = { NULL, NULL };
 static struct child_process pager_process;
 
 static void wait_for_pager(void)
@@ -46,12 +46,14 @@ static void wait_for_pager_signal(int signo)
        raise(signo);
 }
 
-void setup_pager(void)
+const char *git_pager(int stdout_is_tty)
 {
-       const char *pager = getenv("GIT_PAGER");
+       const char *pager;
 
-       if (!isatty(1))
-               return;
+       if (!stdout_is_tty)
+               return NULL;
+
+       pager = getenv("GIT_PAGER");
        if (!pager) {
                if (!pager_program)
                        git_config(git_default_config, NULL);
@@ -60,17 +62,38 @@ void setup_pager(void)
        if (!pager)
                pager = getenv("PAGER");
        if (!pager)
-               pager = "less";
+               pager = DEFAULT_PAGER;
        else if (!*pager || !strcmp(pager, "cat"))
+               pager = NULL;
+
+       return pager;
+}
+
+void setup_pager(void)
+{
+       const char *pager = git_pager(isatty(1));
+
+       if (!pager)
                return;
 
-       spawned_pager = 1; /* means we are emitting to terminal */
+       /*
+        * force computing the width of the terminal before we redirect
+        * the standard output to the pager.
+        */
+       (void) term_columns();
+
+       setenv("GIT_PAGER_IN_USE", "true", 1);
 
        /* spawn the pager */
-       pager_argv[2] = pager;
+       pager_argv[0] = pager;
+       pager_process.use_shell = 1;
        pager_process.argv = pager_argv;
        pager_process.in = -1;
-#ifndef __MINGW32__
+       if (!getenv("LESS")) {
+               static const char *env[] = { "LESS=FRSX", NULL };
+               pager_process.env = env;
+       }
+#ifndef WIN32
        pager_process.preexec_cb = pager_preexec;
 #endif
        if (start_command(&pager_process))
@@ -90,10 +113,37 @@ void setup_pager(void)
 int pager_in_use(void)
 {
        const char *env;
-
-       if (spawned_pager)
-               return 1;
-
        env = getenv("GIT_PAGER_IN_USE");
        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 }
+
+/*
+ * Return cached value (if set) or $COLUMNS environment variable (if
+ * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
+ * and default to 80 if all else fails.
+ */
+int term_columns(void)
+{
+       static int term_columns_at_startup;
+
+       char *col_string;
+       int n_cols;
+
+       if (term_columns_at_startup)
+               return term_columns_at_startup;
+
+       term_columns_at_startup = 80;
+
+       col_string = getenv("COLUMNS");
+       if (col_string && (n_cols = atoi(col_string)) > 0)
+               term_columns_at_startup = n_cols;
+#ifdef TIOCGWINSZ
+       else {
+               struct winsize ws;
+               if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
+                       term_columns_at_startup = ws.ws_col;
+       }
+#endif
+
+       return term_columns_at_startup;
+}