Add back-to-indentation (M-m) for mg

[Henri Kemppainen]

This adds the command that moves the dot to the first non-whitespace
character on the line.

Index: src/usr.bin/mg/def.h
===================================================================
RCS file: /cvs/src/usr.bin/mg/def.h,v
retrieving revision 1.113
diff -u -p -r1.113 def.h
--- src/usr.bin/mg/def.h        30 Jun 2010 19:12:54 -0000      1.113
+++ src/usr.bin/mg/def.h        22 Dec 2010 16:12:15 -0000
@@ -511,6 +511,7 @@ int          indent(int, int);
 int             forwdel(int, int);
 int             backdel(int, int);
 int             space_to_tabstop(int, int);
+int             gotoindent(int, int);
 
 /* extend.c X */
 int             insert(int, int);
Index: src/usr.bin/mg/funmap.c
===================================================================
RCS file: /cvs/src/usr.bin/mg/funmap.c,v
retrieving revision 1.32
diff -u -p -r1.32 funmap.c
--- src/usr.bin/mg/funmap.c     15 Sep 2008 16:13:35 -0000      1.32
+++ src/usr.bin/mg/funmap.c     22 Dec 2010 16:12:15 -0000
@@ -191,6 +191,7 @@ static struct funmap functnames[] = {
        {showcpos, "what-cursor-position",},
        {filewrite, "write-file",},
        {yank, "yank",},
+       {gotoindent, "back-to-indentation",},
        {NULL, NULL,}
 };
 
Index: src/usr.bin/mg/keymap.c
===================================================================
RCS file: /cvs/src/usr.bin/mg/keymap.c,v
retrieving revision 1.43
diff -u -p -r1.43 keymap.c
--- src/usr.bin/mg/keymap.c     27 Aug 2008 04:11:52 -0000      1.43
+++ src/usr.bin/mg/keymap.c     22 Dec 2010 16:12:15 -0000
@@ -241,7 +241,7 @@ static PF metasqf[] = {
 
 static PF metal[] = {
        lowerword,              /* l */
-       rescan,                 /* m */
+       gotoindent,             /* m */
        rescan,                 /* n */
        rescan,                 /* o */
        rescan,                 /* p */
Index: src/usr.bin/mg/mg.1
===================================================================
RCS file: /cvs/src/usr.bin/mg/mg.1,v
retrieving revision 1.47
diff -u -p -r1.47 mg.1
--- src/usr.bin/mg/mg.1 7 Oct 2010 17:08:58 -0000       1.47
+++ src/usr.bin/mg/mg.1 22 Dec 2010 16:12:15 -0000
@@ -230,6 +230,8 @@ kill-word
 forward-word
 .It M-l
 downcase-word
+.It M-m
+back-to-indentation
 .It M-q
 fill-paragraph
 .It M-r
@@ -402,6 +404,8 @@ Set all characters in the region to lowe
 Set characters to lower case, starting at the dot, and ending
 .Va n
 words away.
+.It back-to-indentation
+Move the dot to the first non-whitespace character of the line.
 .It emacs-version
 Return an
 .Nm
Index: src/usr.bin/mg/random.c
===================================================================
RCS file: /cvs/src/usr.bin/mg/random.c,v
retrieving revision 1.26
diff -u -p -r1.26 random.c
--- src/usr.bin/mg/random.c     15 Sep 2008 16:13:35 -0000      1.26
+++ src/usr.bin/mg/random.c     22 Dec 2010 16:12:15 -0000
@@ -440,3 +440,16 @@ space_to_tabstop(int f, int n)
        return (linsert((n << 3) - (curwp->w_doto & 7), ' '));
 }
 #endif /* NOTAB */
+
+/*
+ * Move the dot to the first non-whitespace character of the current line.
+ */
+int
+gotoindent(int f, int n)
+{
+       gotobol(FFRAND, 1);
+       while (curwp->w_doto < llength(curwp->w_dotp) &&
+           (isspace(lgetc(curwp->w_dotp, curwp->w_doto))))
+               ++curwp->w_doto;
+       return (TRUE);
+}