sources/PTYSession.m

@@ -1794,7 +1794,7 @@ ITERM_WEAKLY_REFERENCEABLE
         [self replaceTerminatedShellWithNewInstance];
     } else {
         _shouldRestart = YES;
-        [_shell sendSignal:SIGKILL];
+        [_shell sendSignal:SIGKILL toServer:NO];
     }
 }

sources/PTYTask.h

@@ -70,7 +70,7 @@ extern NSString *kCoprocessStatusChangeNotification;
 - (void)writeTask:(NSData*)data;
-- (void)sendSignal:(int)signo;
+- (void)sendSignal:(int)signo toServer:(BOOL)toServer;
 // Cause the slave to receive a SIGWINCH and change the tty's window size. If `size` equals the
 // tty's current window size then no action is taken.

sources/PTYTask.m

@@ -828,8 +828,11 @@ static int MyForkPty(int *amaster,
     [self.delegate threadedTaskBrokenPipe];
 }
-- (void)sendSignal:(int)signo {
-    if (_serverChildPid != -1) {
+- (void)sendSignal:(int)signo toServer:(BOOL)toServer {
+    if (toServer && _serverPid != -1) {
+        DLog(@"Sending signal to server %@", @(_serverPid));
+        kill(_serverPid, signo);
+    } else if (_serverChildPid != -1) {
         kill(_serverChildPid, signo);
      } else if (_childPid >= 0) {
          kill(_childPid, signo);
@@ -931,7 +934,7 @@ static int MyForkPty(int *amaster,
 - (void)stop {
     self.paused = NO;
     [self stopLogging];
-    [self sendSignal:SIGHUP];
+    [self sendSignal:SIGHUP toServer:NO];
     [self killServerIfRunning];
     if (fd >= 0) {

sources/PseudoTerminal.m

@@ -4427,10 +4427,12 @@ ITERM_WEAKLY_REFERENCEABLE
         [session setIgnoreResizeNotifications:NO];
     }
+    const BOOL willShowTabBar = ([iTermPreferences boolForKey:kPreferenceKeyHideTabBar] &&
+                                 [_contentView.tabView numberOfTabViewItems] > 1 &&
+                                 [_contentView.tabBarControl isHidden]);
     // check window size in case tabs have to be hidden or shown
     if (([_contentView.tabView numberOfTabViewItems] == 1) ||  // just decreased to 1 or increased above 1 and is hidden
-        ([iTermPreferences boolForKey:kPreferenceKeyHideTabBar] &&
-         ([_contentView.tabView numberOfTabViewItems] > 1 && [_contentView.tabBarControl isHidden]))) {
+        willShowTabBar) {
         // Need to change the visibility status of the tab bar control.
         PtyLog(@"tabViewDidChangeNumberOfTabViewItems - calling fitWindowToTab");
@@ -4449,6 +4451,9 @@ ITERM_WEAKLY_REFERENCEABLE
             PTYSession *session = firstTab.sessions.firstObject;
             [[session view] setShowTitle:NO adjustScrollView:YES];
         }
+        if (willShowTabBar && [iTermPreferences intForKey:kPreferenceKeyTabPosition] == PSMTab_LeftTab) {
+            [_contentView willShowTabBar];
+        }
         [self fitWindowToTabs];
         [self repositionWidgets];
         if (wasDraggedFromAnotherWindow_) {

sources/VT100Terminal.m

@@ -685,30 +685,40 @@ static const int kMaxScreenRows = 4096;
                     graphicRendition_.bgColorMode = ColorModeAlternate;
                     break;
                 case VT100CHARATTR_FG_256:
-                    // First subparam means:   # additional subparams:  Accepts optional params:
-                    // 1: transparent          0                        NO
-                    // 2: RGB                  3                        YES
-                    // 3: CMY                  3                        YES
-                    // 4: CMYK                 4                        YES
-                    // 5: Indexed color        1                        NO
+                    // The actual spec for this is called ITU T.416-199303
+                    // You can download it for free! If you prefer to spend money, ISO/IEC 8613-6
+                    // is supposedly the same thing.
                     //
-                    // Optional paramters go at position 7 and 8, and indicate toleranace as an
-                    // integer; and color space (0=CIELUV, 1=CIELAB). Example:
+                    // Here's a sad story about CSI 38:2, which is used to do 24-bit color.
                     //
-                    // CSI 38:2:255:128:64:0:5:1 m
+                    // Lots of terminal emulators, iTerm2 included, misunderstood the spec. That's
+                    // easy to understand if you read it, which I can't recommend doing unless
+                    // you're looking for inspiration for your next Bulwer-Lytton Fiction Contest
+                    // entry.
                     //
-                    // Also accepted for xterm compatibility, but never with optional parameters:
-                    // CSI 38;2;255;128;64 m
+                    // See issue 6377 for more context.
                     //
-                    // Set the foreground color to red=255, green=128, blue=64 with a tolerance of
-                    // 5 in the CIELAB color space. The 0 at the 6th position has no meaning and
-                    // is just a filler.
-                    // 
-                    // For 256-color mode (indexed) use this for the foreground:
-                    // CSI 38;5;N m
-                    // where N is a value between 0 and 255. See the colors described in screen_char_t
-                    // in the comments for fgColorCode.
-
+                    // Ignoring color types we don't support like CMYK, the spec says to do this:
+                    // CSI 38:2:[color space]:[red]:[green]:[blue]:[unused]:[tolerance]:[tolerance colorspace]
+                    //
+                    // Everything after [blue] is optional. Values are decimal numbers in 0...255.
+                    //
+                    // Unfortunately, what was implemented for a long time was this:
+                    // CSI 38:2:[red]:[green]:[blue]:[unused]:[tolerance]:[tolerance colorspace]
+                    //
+                    // And for xterm compatibility, the following was also accepted:
+                    // CSI 38;2;[red];[green];[blue]
+                    //
+                    // The New Order
+                    // -------------
+                    // Tolerance never did anything, so we'll accept this non-standards compliant
+                    // code, which people use:
+                    // CSI 38:2:[red]:[green]:[blue]
+                    //
+                    // As well as the following forms:
+                    // CSI 38:2:[colorspace]:[red]:[green]:[blue]
+                    // CSI 38:2:[colorspace]:[red]:[green]:[blue]:<one or more additional colon-delimited arguments, all ignored>
+                    // CSI 38;2;[red];[green];[blue]   // Notice semicolons in place of colons here
                     if (token.csi->subCount[i] > 0) {
                         // Preferred syntax using colons to delimit subparameters
                         if (token.csi->subCount[i] >= 2 && token.csi->sub[i][0] == 5) {
@@ -718,15 +728,30 @@ static const int kMaxScreenRows = 4096;
                             graphicRendition_.fgBlue = 0;
                             graphicRendition_.fgColorMode = ColorModeNormal;
                         } else if (token.csi->subCount[i] >= 4 && token.csi->sub[i][0] == 2) {
-                            // CSI 38:2:R:G:B m
                             // 24-bit color
-                            graphicRendition_.fgColorCode = token.csi->sub[i][1];
-                            graphicRendition_.fgGreen = token.csi->sub[i][2];
-                            graphicRendition_.fgBlue = token.csi->sub[i][3];
-                            graphicRendition_.fgColorMode = ColorMode24bit;
+                            if (token.csi->subCount[i] >= 5) {
+                                // Spec-compliant. Likely rarely used in 2017.
+                                // CSI 38:2:colorspace:R:G:B m
+                                // TODO: Respect the color space argument. See ITU-T Rec. T.414,
+                                // but good luck actually finding the colour space IDs.
+                                graphicRendition_.fgColorCode = token.csi->sub[i][2];
+                                graphicRendition_.fgGreen = token.csi->sub[i][3];
+                                graphicRendition_.fgBlue = token.csi->sub[i][4];
+                                graphicRendition_.fgColorMode = ColorMode24bit;
+                            } else {
+                                // Misinterpration compliant.
+                                // CSI 38:2:R:G:B m  <- misinterpration compliant
+                                graphicRendition_.fgColorCode = token.csi->sub[i][1];
+                                graphicRendition_.fgGreen = token.csi->sub[i][2];
+                                graphicRendition_.fgBlue = token.csi->sub[i][3];
+                                graphicRendition_.fgColorMode = ColorMode24bit;
+                            }
                         }
                     } else if (token.csi->count - i >= 3 && token.csi->p[i + 1] == 5) {
-                        // CSI 38;5;P m
+                        // For 256-color mode (indexed) use this for the foreground:
+                        // CSI 38;5;N m
+                        // where N is a value between 0 and 255. See the colors described in screen_char_t
+                        // in the comments for fgColorCode.
                         graphicRendition_.fgColorCode = token.csi->p[i + 2];
                         graphicRendition_.fgGreen = 0;
                         graphicRendition_.fgBlue = 0;
@@ -734,6 +759,7 @@ static const int kMaxScreenRows = 4096;
                         i += 2;
                     } else if (token.csi->count - i >= 5 && token.csi->p[i + 1] == 2) {
                         // CSI 38;2;R;G;B m
+                        // Hack for xterm compatibility
                         // 24-bit color support
                         graphicRendition_.fgColorCode = token.csi->p[i + 2];
                         graphicRendition_.fgGreen = token.csi->p[i + 3];

sources/iTermController.m

@@ -1370,7 +1370,10 @@ static iTermController *gSharedInstance;
     assert([iTermAdvancedSettingsModel runJobsInServers]);
     for (iTermRestorableSession *restorableSession in _restorableSessions) {
         for (PTYSession *aSession in restorableSession.sessions) {
-            [aSession.shell sendSignal:SIGHUP];
+            if (aSession.shell.serverPid != -1) {
+                [aSession.shell sendSignal:SIGKILL toServer:YES];
+            }
+            [aSession.shell sendSignal:SIGHUP toServer:YES];
         }
     }
 }

sources/iTermRootTerminalView.h

@@ -69,6 +69,7 @@ extern const CGFloat kHorizontalTabBarHeight;
 @property(nonatomic, readonly) CGFloat tabviewWidth;
 @property(nonatomic, readonly) CGFloat leftTabBarWidth;
+@property(nonatomic, readonly) CGFloat leftTabBarPreferredWidth;
 - (instancetype)initWithFrame:(NSRect)frame
                         color:(NSColor *)color
@@ -93,4 +94,6 @@ extern const CGFloat kHorizontalTabBarHeight;
 - (BOOL)tabBarShouldBeVisibleWithAdditionalTabs:(int)numberOfAdditionalTabs;
+- (void)willShowTabBar;
+
 @end

sources/iTermRootTerminalView.m

@@ -30,7 +30,6 @@ static const CGFloat kMaximumToolbeltSizeAsFractionOfWindow = 0.5;
 @property(nonatomic, retain) SolidColorView *divisionView;
 @property(nonatomic, retain) iTermToolbeltView *toolbelt;
 @property(nonatomic, retain) iTermDragHandleView *leftTabBarDragHandle;
-@property(nonatomic, readonly) CGFloat leftTabBarPreferredWidth;
 @end
@@ -293,6 +292,10 @@ static const CGFloat kMaximumToolbeltSizeAsFractionOfWindow = 0.5;
         DLog(@"repositionWidgets - Set tab view frame to %@", NSStringFromRect(tabViewFrame));
         [self.tabView setFrame:tabViewFrame];
         [self updateDivisionView];
+
+        // Even though it's not visible it needs an accurate number so we can compute the proper
+        // window size when it appears.
+        [self setLeftTabBarWidthFromPreferredWidth];
     } else {
         // The tabBar control is visible.
         DLog(@"repositionWidgets - tabs are visible. Adjusting window size...");
@@ -451,16 +454,33 @@ static const CGFloat kMaximumToolbeltSizeAsFractionOfWindow = 0.5;
     DLog(@"repositionWidgets - return.");
 }
-- (CGFloat)leftTabBarWidthForPreferredWidth:(CGFloat)preferredWidth {
+- (CGFloat)leftTabBarWidthForPreferredWidth:(CGFloat)preferredWidth contentWidth:(CGFloat)contentWidth {
     const CGFloat minimumWidth = 50;
-    const CGFloat maximumWidth = self.bounds.size.width / 3;
-    return  MAX(MIN(maximumWidth, preferredWidth), minimumWidth);
+    const CGFloat maximumWidth = contentWidth / 3;
+    return MAX(MIN(maximumWidth, preferredWidth), minimumWidth);
+}
+
+- (CGFloat)leftTabBarWidthForPreferredWidth:(CGFloat)preferredWidth {
+    return [self leftTabBarWidthForPreferredWidth:preferredWidth contentWidth:self.bounds.size.width];
 }
 - (void)setLeftTabBarWidthFromPreferredWidth {
     _leftTabBarWidth = [self leftTabBarWidthForPreferredWidth:_leftTabBarPreferredWidth];
 }
+- (void)willShowTabBar {
+    const CGFloat minimumWidth = 50;
+    // Given that the New window width (N) = Tab bar width (T) + Content Size (C)
+    // Given that T < N/3 (by leftTabBarWidthForPreferredWidth):
+    // T <= N / 3
+    // T <= 1/3(T+C)
+    // T <= T/3 + C/3
+    // 2/3T <= C/3
+    // T <= C/2
+    const CGFloat maximumWidth = self.bounds.size.width / 2;
+    _leftTabBarWidth = MAX(MIN(maximumWidth, _leftTabBarPreferredWidth), minimumWidth);
+}
+
 #pragma mark - iTermTabBarControlViewDelegate
 - (BOOL)iTermTabBarShouldFlashAutomatically {